Burow Kristina

SEC source: 0001062993-23-018633 · form4.xml · nonDerivative · entry 3

Burow Kristina · CIK 0001569248 · Director · 10% owner

10b5-1 filing: No plan indicated

Ownership: Indirect · By ARCH Venture Fund XII, L.P.

Disclosed balance after: 3,859,898

F3 · price: The price reported in Column 4 is a weighted average price. These shares were purchased in multiple transactions at prices ranging from $13.48 to $14.11, inclusive.

F4 · ownership.nature: Beneficial ownership consists of 3,859,898 shares of common stock held directly by ARCH Venture Fund XII, L.P. (ARCH XII). ARCH Venture Partners XII, L.P. (AVP XII LP) is the general partner of ARCH XII. ARCH Venture Partners XII, LLC (AVP XII LLC) is the general partner of AVP XII LP. Kristina Burow is a member of the investment committee of AVP XII LLC (the AVP XII LLC Committee Member). Each of AVP XII LP and AVP XII LLC may be deemed to beneficially own the shares held by ARCH XII, and the AVP XII LLC Committee Member may be deemed to share the power to direct the disposition and vote of the shares held by ARCH XII. Each of AVP XII LP, AVP XII LLC and the AVP XII LLC Committee Member disclaims beneficial ownership except to the extent of their pecuniary interest therein, if any.

F5 · ownership.nature: As of the date hereof, in addition to securities owned by AVF XII, the reporting person continues to have a direct pecuniary interest and indirect pecuniary interest in securities of the issuer as reported on a Form 4 filed by the reporting person with respect to the issuer on September 20, 2023.

SEC source: 0001062993-23-018633 · form4.xml · nonDerivative · entry 2

Burow Kristina · CIK 0001569248 · Director · 10% owner

10b5-1 filing: No plan indicated

Ownership: Indirect · By ARCH Venture Fund XII, L.P.

Disclosed balance after: 3,825,338

F2 · price: The price reported in Column 4 is a weighted average price. These shares were purchased in multiple transactions at prices ranging from $13.34 to $14.23, inclusive.

F4 · ownership.nature: Beneficial ownership consists of 3,859,898 shares of common stock held directly by ARCH Venture Fund XII, L.P. (ARCH XII). ARCH Venture Partners XII, L.P. (AVP XII LP) is the general partner of ARCH XII. ARCH Venture Partners XII, LLC (AVP XII LLC) is the general partner of AVP XII LP. Kristina Burow is a member of the investment committee of AVP XII LLC (the AVP XII LLC Committee Member). Each of AVP XII LP and AVP XII LLC may be deemed to beneficially own the shares held by ARCH XII, and the AVP XII LLC Committee Member may be deemed to share the power to direct the disposition and vote of the shares held by ARCH XII. Each of AVP XII LP, AVP XII LLC and the AVP XII LLC Committee Member disclaims beneficial ownership except to the extent of their pecuniary interest therein, if any.

F5 · ownership.nature: As of the date hereof, in addition to securities owned by AVF XII, the reporting person continues to have a direct pecuniary interest and indirect pecuniary interest in securities of the issuer as reported on a Form 4 filed by the reporting person with respect to the issuer on September 20, 2023.

SEC source: 0001062993-23-018633 · form4.xml · nonDerivative · entry 1

Burow Kristina · CIK 0001569248 · Director · 10% owner

10b5-1 filing: No plan indicated

Ownership: Indirect · By ARCH Venture Fund XII, L.P.

Disclosed balance after: 3,800,228

F1 · price: The price reported in Column 4 is a weighted average price. These shares were purchased in multiple transactions at prices ranging from $12.34 to $13.33, inclusive. The reporting person undertakes to provide to NMRA, any security holder of NMRA, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in footnotes (1), (2) and (3) to this Form 4.

F4 · ownership.nature: Beneficial ownership consists of 3,859,898 shares of common stock held directly by ARCH Venture Fund XII, L.P. (ARCH XII). ARCH Venture Partners XII, L.P. (AVP XII LP) is the general partner of ARCH XII. ARCH Venture Partners XII, LLC (AVP XII LLC) is the general partner of AVP XII LP. Kristina Burow is a member of the investment committee of AVP XII LLC (the AVP XII LLC Committee Member). Each of AVP XII LP and AVP XII LLC may be deemed to beneficially own the shares held by ARCH XII, and the AVP XII LLC Committee Member may be deemed to share the power to direct the disposition and vote of the shares held by ARCH XII. Each of AVP XII LP, AVP XII LLC and the AVP XII LLC Committee Member disclaims beneficial ownership except to the extent of their pecuniary interest therein, if any.

F5 · ownership.nature: As of the date hereof, in addition to securities owned by AVF XII, the reporting person continues to have a direct pecuniary interest and indirect pecuniary interest in securities of the issuer as reported on a Form 4 filed by the reporting person with respect to the issuer on September 20, 2023.

SEC source: 0001062993-23-018548 · form4.xml · nonDerivative · entry 2

Burow Kristina · CIK 0001569248 · Director · 10% owner

10b5-1 filing: No plan indicated

Ownership: Indirect · By ARCH Venture Fund XII, L.P.

Disclosed balance after: 3,783,387

F2 · price: The price reported in Column 4 is a weighted average price. These shares were purchased in multiple transactions at prices ranging from $11.94 to $12.68, inclusive.

F3 · ownership.nature: Beneficial ownership consists of 3,783,387 shares of common stock held directly by ARCH Venture Fund XII, L.P. (ARCH XII). ARCH Venture Partners XII, L.P. (AVP XII LP) is the general partner of ARCH XII. ARCH Venture Partners XII, LLC (AVP XII LLC) is the general partner of AVP XII LP. Kristina Burow is a member of the investment committee of AVP XII LLC (the AVP XII LLC Committee Member). Each of AVP XII LP and AVP XII LLC may be deemed to beneficially own the shares held by ARCH XII, and the AVP XII LLC Committee Member may be deemed to share the power to direct the disposition and vote of the shares held by ARCH XII. Each of AVP XII LP, AVP XII LLC and the AVP XII LLC Committee Member disclaims beneficial ownership except to the extent of their pecuniary interest therein, if any.

F4 · ownership.nature: As of the date hereof, in addition to securities owned by AVF XII, the reporting person continues to have a direct pecuniary interest and indirect pecuniary interest in securities of the issuer as reported on a Form 4 filed by the reporting person with respect to the issuer on September 20, 2023.

SEC source: 0001062993-23-018548 · form4.xml · nonDerivative · entry 1

Burow Kristina · CIK 0001569248 · Director · 10% owner

10b5-1 filing: No plan indicated

Ownership: Indirect · By ARCH Venture Fund XII, L.P.

Disclosed balance after: 3,758,883

F1 · price: The price reported in Column 4 is a weighted average price. These shares were purchased in multiple transactions at prices ranging from $11.32 to $12.04, inclusive. The reporting person undertakes to provide to NMRA, any security holder of NMRA, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in footnotes (1) and (2) to this Form 4.

F3 · ownership.nature: Beneficial ownership consists of 3,783,387 shares of common stock held directly by ARCH Venture Fund XII, L.P. (ARCH XII). ARCH Venture Partners XII, L.P. (AVP XII LP) is the general partner of ARCH XII. ARCH Venture Partners XII, LLC (AVP XII LLC) is the general partner of AVP XII LP. Kristina Burow is a member of the investment committee of AVP XII LLC (the AVP XII LLC Committee Member). Each of AVP XII LP and AVP XII LLC may be deemed to beneficially own the shares held by ARCH XII, and the AVP XII LLC Committee Member may be deemed to share the power to direct the disposition and vote of the shares held by ARCH XII. Each of AVP XII LP, AVP XII LLC and the AVP XII LLC Committee Member disclaims beneficial ownership except to the extent of their pecuniary interest therein, if any.

F4 · ownership.nature: As of the date hereof, in addition to securities owned by AVF XII, the reporting person continues to have a direct pecuniary interest and indirect pecuniary interest in securities of the issuer as reported on a Form 4 filed by the reporting person with respect to the issuer on September 20, 2023.

SEC source: 0001062993-23-018468 · form4.xml · nonDerivative · entry 3

Burow Kristina · CIK 0001569248 · Director · 10% owner

10b5-1 filing: No plan indicated

Ownership: Indirect · By ARCH Venture Fund XII, L.P.

Disclosed balance after: 3,724,883

F3 · price: The price reported in Column 4 is a weighted average price. These shares were purchased in multiple transactions at prices ranging from $11.50 to $12.14, inclusive.

F4 · ownership.nature: Beneficial ownership consists of 3,724,883 shares of common stock held directly by ARCH Venture Fund XII, L.P. (ARCH XII). ARCH Venture Partners XII, L.P. (AVP XII LP) is the general partner of ARCH XII. ARCH Venture Partners XII, LLC (AVP XII LLC) is the general partner of AVP XII LP. Kristina Burow is a member of the investment committee of AVP XII LLC (the AVP XII LLC Committee Member). Each of AVP XII LP and AVP XII LLC may be deemed to beneficially own the shares held by ARCH XII, and the AVP XII LLC Committee Member may be deemed to share the power to direct the disposition and vote of the shares held by ARCH XII. Each of AVP XII LP, AVP XII LLC and the AVP XII LLC Committee Member disclaims beneficial ownership except to the extent of their pecuniary interest therein, if any.

F5 · ownership.nature: As of the date hereof, in addition to securities owned by AVF XII, the reporting person continues to have a direct pecuniary interest and indirect pecuniary interest in securities of the issuer as reported on a Form 4 filed by the reporting person with respect to the issuer on September 20, 2023.

SEC source: 0001062993-23-018468 · form4.xml · nonDerivative · entry 2

Burow Kristina · CIK 0001569248 · Director · 10% owner

10b5-1 filing: No plan indicated

Ownership: Indirect · By ARCH Venture Fund XII, L.P.

Disclosed balance after: 3,694,916

F2 · price: The price reported in Column 4 is a weighted average price. These shares were purchased in multiple transactions at prices ranging from $10.50 to $11.49, inclusive.

F4 · ownership.nature: Beneficial ownership consists of 3,724,883 shares of common stock held directly by ARCH Venture Fund XII, L.P. (ARCH XII). ARCH Venture Partners XII, L.P. (AVP XII LP) is the general partner of ARCH XII. ARCH Venture Partners XII, LLC (AVP XII LLC) is the general partner of AVP XII LP. Kristina Burow is a member of the investment committee of AVP XII LLC (the AVP XII LLC Committee Member). Each of AVP XII LP and AVP XII LLC may be deemed to beneficially own the shares held by ARCH XII, and the AVP XII LLC Committee Member may be deemed to share the power to direct the disposition and vote of the shares held by ARCH XII. Each of AVP XII LP, AVP XII LLC and the AVP XII LLC Committee Member disclaims beneficial ownership except to the extent of their pecuniary interest therein, if any.

F5 · ownership.nature: As of the date hereof, in addition to securities owned by AVF XII, the reporting person continues to have a direct pecuniary interest and indirect pecuniary interest in securities of the issuer as reported on a Form 4 filed by the reporting person with respect to the issuer on September 20, 2023.

SEC source: 0001062993-23-018468 · form4.xml · nonDerivative · entry 1

Burow Kristina · CIK 0001569248 · Director · 10% owner

10b5-1 filing: No plan indicated

Ownership: Indirect · By ARCH Venture Fund XII, L.P.

Disclosed balance after: 3,664,143

F1 · price: The price reported in Column 4 is a weighted average price. These shares were purchased in multiple transactions at prices ranging from $10.50 to $11.48, inclusive. The reporting person undertakes to provide to NMRA, any security holder of NMRA, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in footnotes (1),(2), and (3) to this Form 4.

F4 · ownership.nature: Beneficial ownership consists of 3,724,883 shares of common stock held directly by ARCH Venture Fund XII, L.P. (ARCH XII). ARCH Venture Partners XII, L.P. (AVP XII LP) is the general partner of ARCH XII. ARCH Venture Partners XII, LLC (AVP XII LLC) is the general partner of AVP XII LP. Kristina Burow is a member of the investment committee of AVP XII LLC (the AVP XII LLC Committee Member). Each of AVP XII LP and AVP XII LLC may be deemed to beneficially own the shares held by ARCH XII, and the AVP XII LLC Committee Member may be deemed to share the power to direct the disposition and vote of the shares held by ARCH XII. Each of AVP XII LP, AVP XII LLC and the AVP XII LLC Committee Member disclaims beneficial ownership except to the extent of their pecuniary interest therein, if any.

F5 · ownership.nature: As of the date hereof, in addition to securities owned by AVF XII, the reporting person continues to have a direct pecuniary interest and indirect pecuniary interest in securities of the issuer as reported on a Form 4 filed by the reporting person with respect to the issuer on September 20, 2023.

SEC source: 0001610717-23-000291 · form4.xml · derivative · entry 13

Burow Kristina · CIK 0001569248 · Director · 10% owner

10b5-1 filing: No plan indicated

Ownership: Indirect · See Footnote

Disclosed balance after: 0

Underlying: Common Stock · 2,124,143 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · derivative.exercise_price: The shares of Series A-1 Preferred Stock, Series A-2 Preferred Stock and Series B Preferred Stock of the Issuer automatically converted on a 1-for-1 basis into Common Stock of the Issuer immediately prior to the closing of the Issuer's initial public offering.

F1 · price: The shares of Series A-1 Preferred Stock, Series A-2 Preferred Stock and Series B Preferred Stock of the Issuer automatically converted on a 1-for-1 basis into Common Stock of the Issuer immediately prior to the closing of the Issuer's initial public offering.

F1 · derivative.exercise_date: The shares of Series A-1 Preferred Stock, Series A-2 Preferred Stock and Series B Preferred Stock of the Issuer automatically converted on a 1-for-1 basis into Common Stock of the Issuer immediately prior to the closing of the Issuer's initial public offering.

F1 · derivative.expiration_date: The shares of Series A-1 Preferred Stock, Series A-2 Preferred Stock and Series B Preferred Stock of the Issuer automatically converted on a 1-for-1 basis into Common Stock of the Issuer immediately prior to the closing of the Issuer's initial public offering.

F8 · ownership.nature: Represents shares held directly by ARCH Venture Fund XII, L.P. (ARCH XII). ARCH Venture Partners XII, L.P. (AVP XII LP) is the general partner of ARCH XII. ARCH Venture Partners XII, LLC (AVP XII LLC) is the general partner of AVP XII LP. Keith Crandell, Kristina Burow, Steven Gillis and Robert Nelsen comprise the investment committee of AVP XII LLC (the AVP XII LLC Committee Members). AVP XII LLC may be deemed to beneficially own the shares held by ARCH XII, and each of the AVP XII LLC Committee Members may be deemed to share the power to direct the disposition and vote of the shares held by ARCH XII. AVP XII LLC Committee Members each disclaim beneficial ownership except to the extent of their pecuniary interest therein, if any.

SEC source: 0001610717-23-000291 · form4.xml · derivative · entry 12

Burow Kristina · CIK 0001569248 · Director · 10% owner

10b5-1 filing: No plan indicated

Ownership: Indirect · See Footnotes

Disclosed balance after: 0

Underlying: Common Stock · 6,576,400 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · derivative.exercise_price: The shares of Series A-1 Preferred Stock, Series A-2 Preferred Stock and Series B Preferred Stock of the Issuer automatically converted on a 1-for-1 basis into Common Stock of the Issuer immediately prior to the closing of the Issuer's initial public offering.

F1 · price: The shares of Series A-1 Preferred Stock, Series A-2 Preferred Stock and Series B Preferred Stock of the Issuer automatically converted on a 1-for-1 basis into Common Stock of the Issuer immediately prior to the closing of the Issuer's initial public offering.

F1 · derivative.exercise_date: The shares of Series A-1 Preferred Stock, Series A-2 Preferred Stock and Series B Preferred Stock of the Issuer automatically converted on a 1-for-1 basis into Common Stock of the Issuer immediately prior to the closing of the Issuer's initial public offering.

F1 · derivative.expiration_date: The shares of Series A-1 Preferred Stock, Series A-2 Preferred Stock and Series B Preferred Stock of the Issuer automatically converted on a 1-for-1 basis into Common Stock of the Issuer immediately prior to the closing of the Issuer's initial public offering.

F6 · ownership.nature: Represents shares held directly by ARCH Venture Fund X Overage, L.P. (ARCH X Overage). ARCH Venture Partners X Overage, L.P. (AVP X Overage LP) is the sole general partner of ARCH X Overage.

F7 · ownership.nature: ARCH Venture Partners X, LLC (AVP X LLC) is the sole general partner of each of AVP X LP and AVP X Overage LP. Keith Crandell, Kristina Burow, Steven Gillis and Robert Nelsen comprise the investment committee of AVP X LLC (the AVP X Committee Members). AVP X LLC may be deemed to beneficially own the shares held by ARCH X and ARCH X Overage, and each of the AVP X Committee Members may be deemed to share the power to direct the disposition and vote of the shares held by ARCH X and ARCH X Overage. AVP X Committee Members each disclaim beneficial ownership except to the extent of their pecuniary interest therein, if any.

SEC source: 0001610717-23-000291 · form4.xml · derivative · entry 11

Burow Kristina · CIK 0001569248 · Director · 10% owner

10b5-1 filing: No plan indicated

Ownership: Indirect · See Footnotes

Disclosed balance after: 0

Underlying: Common Stock · 6,895,021 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · derivative.exercise_price: The shares of Series A-1 Preferred Stock, Series A-2 Preferred Stock and Series B Preferred Stock of the Issuer automatically converted on a 1-for-1 basis into Common Stock of the Issuer immediately prior to the closing of the Issuer's initial public offering.

F1 · price: The shares of Series A-1 Preferred Stock, Series A-2 Preferred Stock and Series B Preferred Stock of the Issuer automatically converted on a 1-for-1 basis into Common Stock of the Issuer immediately prior to the closing of the Issuer's initial public offering.

F1 · derivative.exercise_date: The shares of Series A-1 Preferred Stock, Series A-2 Preferred Stock and Series B Preferred Stock of the Issuer automatically converted on a 1-for-1 basis into Common Stock of the Issuer immediately prior to the closing of the Issuer's initial public offering.

F1 · derivative.expiration_date: The shares of Series A-1 Preferred Stock, Series A-2 Preferred Stock and Series B Preferred Stock of the Issuer automatically converted on a 1-for-1 basis into Common Stock of the Issuer immediately prior to the closing of the Issuer's initial public offering.

F5 · ownership.nature: Represents shares held directly by ARCH Venture Fund X, L.P. (ARCH X). ARCH Venture Partners X, L.P. (AVP X LP) is the sole general partner of ARCH X.

F7 · ownership.nature: ARCH Venture Partners X, LLC (AVP X LLC) is the sole general partner of each of AVP X LP and AVP X Overage LP. Keith Crandell, Kristina Burow, Steven Gillis and Robert Nelsen comprise the investment committee of AVP X LLC (the AVP X Committee Members). AVP X LLC may be deemed to beneficially own the shares held by ARCH X and ARCH X Overage, and each of the AVP X Committee Members may be deemed to share the power to direct the disposition and vote of the shares held by ARCH X and ARCH X Overage. AVP X Committee Members each disclaim beneficial ownership except to the extent of their pecuniary interest therein, if any.

SEC source: 0001610717-23-000291 · form4.xml · derivative · entry 10

Burow Kristina · CIK 0001569248 · Director · 10% owner

10b5-1 filing: No plan indicated

Ownership: Indirect · See Footnotes

Disclosed balance after: 0

Underlying: Common Stock · 1,144,973 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · derivative.exercise_price: The shares of Series A-1 Preferred Stock, Series A-2 Preferred Stock and Series B Preferred Stock of the Issuer automatically converted on a 1-for-1 basis into Common Stock of the Issuer immediately prior to the closing of the Issuer's initial public offering.

F1 · price: The shares of Series A-1 Preferred Stock, Series A-2 Preferred Stock and Series B Preferred Stock of the Issuer automatically converted on a 1-for-1 basis into Common Stock of the Issuer immediately prior to the closing of the Issuer's initial public offering.

F1 · derivative.exercise_date: The shares of Series A-1 Preferred Stock, Series A-2 Preferred Stock and Series B Preferred Stock of the Issuer automatically converted on a 1-for-1 basis into Common Stock of the Issuer immediately prior to the closing of the Issuer's initial public offering.

F1 · derivative.expiration_date: The shares of Series A-1 Preferred Stock, Series A-2 Preferred Stock and Series B Preferred Stock of the Issuer automatically converted on a 1-for-1 basis into Common Stock of the Issuer immediately prior to the closing of the Issuer's initial public offering.

F3 · ownership.nature: Represents shares held directly by ARCH Venture Fund VIII Overage, L.P. (ARCH VIII Overage). ARCH Venture Partners VIII, LLC (AVP VIII LLC) is the general partner of ARCH VIII Overage. Clinton Bybee, Keith Crandell and Robert Nelsen are the managing directors of AVP VIII LLC (the AVP VIII LLC Managing Directors). AVP VIII LLC may be deemed to beneficially own the shares held by ARCH VIII Overage, and each of the AVP VIII LLC Managing Directors may be deemed to share the power to direct the disposition and vote of the shares held by ARCH VIII Overage. AVP VIII LLC Managing Directors each disclaim beneficial ownership except to the extent of their pecuniary interest therein, if any. The Reporting Person is a managing director at AVP VIII LLC and owns an interest in AVP VIII LLC but does not have voting or investment control over the shares held by ARCH VIII Overage.

F4 · ownership.nature: The Reporting Person disclaims beneficial ownership of such shares, except to the extent of any pecuniary interest therein.

SEC source: 0001610717-23-000291 · form4.xml · derivative · entry 9

Burow Kristina · CIK 0001569248 · Director · 10% owner

10b5-1 filing: No plan indicated

Ownership: Indirect · See Footnotes

Disclosed balance after: 0

Underlying: Common Stock · 684,167 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · derivative.exercise_price: The shares of Series A-1 Preferred Stock, Series A-2 Preferred Stock and Series B Preferred Stock of the Issuer automatically converted on a 1-for-1 basis into Common Stock of the Issuer immediately prior to the closing of the Issuer's initial public offering.

F1 · price: The shares of Series A-1 Preferred Stock, Series A-2 Preferred Stock and Series B Preferred Stock of the Issuer automatically converted on a 1-for-1 basis into Common Stock of the Issuer immediately prior to the closing of the Issuer's initial public offering.

F1 · derivative.exercise_date: The shares of Series A-1 Preferred Stock, Series A-2 Preferred Stock and Series B Preferred Stock of the Issuer automatically converted on a 1-for-1 basis into Common Stock of the Issuer immediately prior to the closing of the Issuer's initial public offering.

F1 · derivative.expiration_date: The shares of Series A-1 Preferred Stock, Series A-2 Preferred Stock and Series B Preferred Stock of the Issuer automatically converted on a 1-for-1 basis into Common Stock of the Issuer immediately prior to the closing of the Issuer's initial public offering.

F2 · ownership.nature: Represents shares held directly by ARCH Venture Fund VII, L.P. (ARCH VII). ARCH Venture Partners VII, L.P. (AVP VII LP) is the sole general partner of ARCH VII, and ARCH Venture Partners VII, LLC (AVP VII LLC) is the sole general partner of AVP VII LP. Clinton Bybee, Keith Crandell and Robert Nelsen are the managing directors of AVP VII LLC (AVP VII LLC Managing Directors). AVP VII LLC may be deemed to beneficially own the shares held by ARCH VII, and each of the AVP VII LLC Managing Directors may be deemed to share the power to direct the disposition and vote of the shares held by ARCH VII. AVP VII LLC Managing Directors each disclaim beneficial ownership except to the extent of their pecuniary interest therein, if any. The Reporting Person is a managing director at AVP VII LLC and owns an interest in AVP VII LP but does not have voting or investment control over the shares held by ARCH VII.

F4 · ownership.nature: The Reporting Person disclaims beneficial ownership of such shares, except to the extent of any pecuniary interest therein.

SEC source: 0001610717-23-000291 · form4.xml · derivative · entry 8

Burow Kristina · CIK 0001569248 · Director · 10% owner

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 13,620 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · derivative.exercise_price: The shares of Series A-1 Preferred Stock, Series A-2 Preferred Stock and Series B Preferred Stock of the Issuer automatically converted on a 1-for-1 basis into Common Stock of the Issuer immediately prior to the closing of the Issuer's initial public offering.

F1 · price: The shares of Series A-1 Preferred Stock, Series A-2 Preferred Stock and Series B Preferred Stock of the Issuer automatically converted on a 1-for-1 basis into Common Stock of the Issuer immediately prior to the closing of the Issuer's initial public offering.

F1 · derivative.exercise_date: The shares of Series A-1 Preferred Stock, Series A-2 Preferred Stock and Series B Preferred Stock of the Issuer automatically converted on a 1-for-1 basis into Common Stock of the Issuer immediately prior to the closing of the Issuer's initial public offering.

F1 · derivative.expiration_date: The shares of Series A-1 Preferred Stock, Series A-2 Preferred Stock and Series B Preferred Stock of the Issuer automatically converted on a 1-for-1 basis into Common Stock of the Issuer immediately prior to the closing of the Issuer's initial public offering.

SEC source: 0001610717-23-000291 · form4.xml · nonDerivative · entry 7

Burow Kristina · CIK 0001569248 · Director · 10% owner

10b5-1 filing: No plan indicated

Ownership: Indirect · See Footnote

Disclosed balance after: 3,624,143

F8 · ownership.nature: Represents shares held directly by ARCH Venture Fund XII, L.P. (ARCH XII). ARCH Venture Partners XII, L.P. (AVP XII LP) is the general partner of ARCH XII. ARCH Venture Partners XII, LLC (AVP XII LLC) is the general partner of AVP XII LP. Keith Crandell, Kristina Burow, Steven Gillis and Robert Nelsen comprise the investment committee of AVP XII LLC (the AVP XII LLC Committee Members). AVP XII LLC may be deemed to beneficially own the shares held by ARCH XII, and each of the AVP XII LLC Committee Members may be deemed to share the power to direct the disposition and vote of the shares held by ARCH XII. AVP XII LLC Committee Members each disclaim beneficial ownership except to the extent of their pecuniary interest therein, if any.

SEC source: 0001610717-23-000291 · form4.xml · nonDerivative · entry 6

Burow Kristina · CIK 0001569248 · Director · 10% owner

10b5-1 filing: No plan indicated

Ownership: Indirect · See Footnote

Disclosed balance after: 2,124,143

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · price: The shares of Series A-1 Preferred Stock, Series A-2 Preferred Stock and Series B Preferred Stock of the Issuer automatically converted on a 1-for-1 basis into Common Stock of the Issuer immediately prior to the closing of the Issuer's initial public offering.

F8 · ownership.nature: Represents shares held directly by ARCH Venture Fund XII, L.P. (ARCH XII). ARCH Venture Partners XII, L.P. (AVP XII LP) is the general partner of ARCH XII. ARCH Venture Partners XII, LLC (AVP XII LLC) is the general partner of AVP XII LP. Keith Crandell, Kristina Burow, Steven Gillis and Robert Nelsen comprise the investment committee of AVP XII LLC (the AVP XII LLC Committee Members). AVP XII LLC may be deemed to beneficially own the shares held by ARCH XII, and each of the AVP XII LLC Committee Members may be deemed to share the power to direct the disposition and vote of the shares held by ARCH XII. AVP XII LLC Committee Members each disclaim beneficial ownership except to the extent of their pecuniary interest therein, if any.

SEC source: 0001610717-23-000291 · form4.xml · nonDerivative · entry 5

Burow Kristina · CIK 0001569248 · Director · 10% owner

10b5-1 filing: No plan indicated

Ownership: Indirect · See Footnotes

Disclosed balance after: 11,886,758

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · price: The shares of Series A-1 Preferred Stock, Series A-2 Preferred Stock and Series B Preferred Stock of the Issuer automatically converted on a 1-for-1 basis into Common Stock of the Issuer immediately prior to the closing of the Issuer's initial public offering.

F6 · ownership.nature: Represents shares held directly by ARCH Venture Fund X Overage, L.P. (ARCH X Overage). ARCH Venture Partners X Overage, L.P. (AVP X Overage LP) is the sole general partner of ARCH X Overage.

F7 · ownership.nature: ARCH Venture Partners X, LLC (AVP X LLC) is the sole general partner of each of AVP X LP and AVP X Overage LP. Keith Crandell, Kristina Burow, Steven Gillis and Robert Nelsen comprise the investment committee of AVP X LLC (the AVP X Committee Members). AVP X LLC may be deemed to beneficially own the shares held by ARCH X and ARCH X Overage, and each of the AVP X Committee Members may be deemed to share the power to direct the disposition and vote of the shares held by ARCH X and ARCH X Overage. AVP X Committee Members each disclaim beneficial ownership except to the extent of their pecuniary interest therein, if any.

SEC source: 0001610717-23-000291 · form4.xml · nonDerivative · entry 4

Burow Kristina · CIK 0001569248 · Director · 10% owner

10b5-1 filing: No plan indicated

Ownership: Indirect · See Footnotes

Disclosed balance after: 12,205,379

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · price: The shares of Series A-1 Preferred Stock, Series A-2 Preferred Stock and Series B Preferred Stock of the Issuer automatically converted on a 1-for-1 basis into Common Stock of the Issuer immediately prior to the closing of the Issuer's initial public offering.

F5 · ownership.nature: Represents shares held directly by ARCH Venture Fund X, L.P. (ARCH X). ARCH Venture Partners X, L.P. (AVP X LP) is the sole general partner of ARCH X.

F7 · ownership.nature: ARCH Venture Partners X, LLC (AVP X LLC) is the sole general partner of each of AVP X LP and AVP X Overage LP. Keith Crandell, Kristina Burow, Steven Gillis and Robert Nelsen comprise the investment committee of AVP X LLC (the AVP X Committee Members). AVP X LLC may be deemed to beneficially own the shares held by ARCH X and ARCH X Overage, and each of the AVP X Committee Members may be deemed to share the power to direct the disposition and vote of the shares held by ARCH X and ARCH X Overage. AVP X Committee Members each disclaim beneficial ownership except to the extent of their pecuniary interest therein, if any.

SEC source: 0001610717-23-000291 · form4.xml · nonDerivative · entry 3

Burow Kristina · CIK 0001569248 · Director · 10% owner

10b5-1 filing: No plan indicated

Ownership: Indirect · See Footnotes

Disclosed balance after: 1,144,973

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · price: The shares of Series A-1 Preferred Stock, Series A-2 Preferred Stock and Series B Preferred Stock of the Issuer automatically converted on a 1-for-1 basis into Common Stock of the Issuer immediately prior to the closing of the Issuer's initial public offering.

F3 · ownership.nature: Represents shares held directly by ARCH Venture Fund VIII Overage, L.P. (ARCH VIII Overage). ARCH Venture Partners VIII, LLC (AVP VIII LLC) is the general partner of ARCH VIII Overage. Clinton Bybee, Keith Crandell and Robert Nelsen are the managing directors of AVP VIII LLC (the AVP VIII LLC Managing Directors). AVP VIII LLC may be deemed to beneficially own the shares held by ARCH VIII Overage, and each of the AVP VIII LLC Managing Directors may be deemed to share the power to direct the disposition and vote of the shares held by ARCH VIII Overage. AVP VIII LLC Managing Directors each disclaim beneficial ownership except to the extent of their pecuniary interest therein, if any. The Reporting Person is a managing director at AVP VIII LLC and owns an interest in AVP VIII LLC but does not have voting or investment control over the shares held by ARCH VIII Overage.

F4 · ownership.nature: The Reporting Person disclaims beneficial ownership of such shares, except to the extent of any pecuniary interest therein.

SEC source: 0001610717-23-000291 · form4.xml · nonDerivative · entry 2

Burow Kristina · CIK 0001569248 · Director · 10% owner

10b5-1 filing: No plan indicated

Ownership: Indirect · See Footnotes

Disclosed balance after: 684,167

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · price: The shares of Series A-1 Preferred Stock, Series A-2 Preferred Stock and Series B Preferred Stock of the Issuer automatically converted on a 1-for-1 basis into Common Stock of the Issuer immediately prior to the closing of the Issuer's initial public offering.

F2 · ownership.nature: Represents shares held directly by ARCH Venture Fund VII, L.P. (ARCH VII). ARCH Venture Partners VII, L.P. (AVP VII LP) is the sole general partner of ARCH VII, and ARCH Venture Partners VII, LLC (AVP VII LLC) is the sole general partner of AVP VII LP. Clinton Bybee, Keith Crandell and Robert Nelsen are the managing directors of AVP VII LLC (AVP VII LLC Managing Directors). AVP VII LLC may be deemed to beneficially own the shares held by ARCH VII, and each of the AVP VII LLC Managing Directors may be deemed to share the power to direct the disposition and vote of the shares held by ARCH VII. AVP VII LLC Managing Directors each disclaim beneficial ownership except to the extent of their pecuniary interest therein, if any. The Reporting Person is a managing director at AVP VII LLC and owns an interest in AVP VII LP but does not have voting or investment control over the shares held by ARCH VII.

F4 · ownership.nature: The Reporting Person disclaims beneficial ownership of such shares, except to the extent of any pecuniary interest therein.

SEC source: 0001610717-23-000291 · form4.xml · nonDerivative · entry 1

Burow Kristina · CIK 0001569248 · Director · 10% owner

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 13,620

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · price: The shares of Series A-1 Preferred Stock, Series A-2 Preferred Stock and Series B Preferred Stock of the Issuer automatically converted on a 1-for-1 basis into Common Stock of the Issuer immediately prior to the closing of the Issuer's initial public offering.

SEC source: 0001610717-23-000284 · form4.xml · derivative · entry 1

Burow Kristina · CIK 0001569248 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 46,455

Underlying: Common Stock · 46,455 shares

Expires 2033-09-13

F1 · derivative.exercise_date: 1/36th of the shares subject to the option vest on each monthly anniversary measured from September 14, 2023 (the "Vesting Commencement Date"), such that 100% of the shares subject to the option will be fully vested and exercisable on the third anniversary of the Vesting Commencement Date.

SEC source: 0001062993-23-016233 · form4.xml · nonDerivative · entry 1

ARCH Venture Fund XI, L.P. · CIK 0001831802 · 10% owner

ARCH Venture Partners XI, L.P. · CIK 0001847567 · 10% owner

ARCH Venture Partners XI, LLC · CIK 0001847601 · 10% owner

NELSEN ROBERT · CIK 0001219042 · 10% owner

Burow Kristina · CIK 0001569248 · 10% owner

GILLIS STEVEN · CIK 0001229592 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 0

F1 · kind: On July 28, 2023, the Issuer redeemed all of its outstanding shares of Class A common stock that were publicly traded for a redemption price of approximately $10.31 per share.

F1 · price: On July 28, 2023, the Issuer redeemed all of its outstanding shares of Class A common stock that were publicly traded for a redemption price of approximately $10.31 per share.

F2 · ownership.direct: This Form 4 is filed jointly by ARCH Venture Fund XI, L.P. ("AVF"), ARCH Venture Partners XI, L.P. ("AVP LP"), ARCH Venture Partners XI, LLC ("AVP LLC"), Kristina Burow, Robert Nelsen and Steven Gillis (collectively, the "Reporting Persons"). Keith Crandell has direct ownership of the Issuer's Class B Common Stock, as well as indirect pecuniary ownership of the Issuer's Class B Common Stock and shares of Class A common stock purchased in a private placement and is filing his own Form 4 separately. Burow, Crandell, Nelsen and Gillis comprise the investment committee of AVP LLC (the AVP X Committee Members). Each of the Reporting Persons is a member of a Section 13(d) group. Each of the Reporting Persons disclaims beneficial ownership of the securities reported herein except to the extent of such Reporting Person's pecuniary interest therein.

SEC source: 0001415889-23-010215 · form4-06232023_110628.xml · derivative · entry 1

Burow Kristina · CIK 0001569248 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 36,000

Underlying: Common Stock · 36,000 shares

Expires 2033-06-21

F1 · derivative.exercise_date: This option shall vest and become fully exercisable on the earlier of the first anniversary following the date of grant or on the date of the Issuer's next Annual Meeting subject to continued service to the Issuer through such date.

SEC source: 0001728117-23-000078 · wf-form4_168634158506142.xml · derivative · entry 1

Burow Kristina · CIK 0001569248 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 35,000

Underlying: Common Stock · 35,000 shares

Expires 2033-06-07

F1 · shares: Award made pursuant to Non-Employee Director Compensation Program.

F2 · derivative.exercise_date: The entire number of shares subject to this option becomes fully vested and exercisable on the first to occur of (a) the first anniversary of the grant date or (b) the next occurring annual meeting of the Issuer's stockholders, subject to the Reporting Person's continued service on the board of directors of the Issuer through such vesting date.

SEC source: 0000950170-23-027060 · ownership.xml · derivative · entry 4

Burow Kristina · CIK 0001569248 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 16,532

Underlying: Common Stock · 16,532 shares

Expires 2033-06-06

F4 · derivative.exercise_date: The option vests in full on the earlier of the first anniversary of the date of grant and the date of the next year's annual meeting of stockholders, subject to the reporting person's continued service to the board of directors of Beam Therapeutics Inc. through the vesting date.

SEC source: 0001628280-22-027125 · wf-form4_166682887797580.xml · derivative · entry 8

ARCH Venture Partners X, LLC · CIK 0001769012 · 10% owner

ARCH Venture Partners X, L.P. · CIK 0001782583 · 10% owner

ARCH Venture Partners X Overage, L.P. · CIK 0001768905 · 10% owner

ARCH Venture Fund X, L.P. · CIK 0001757011 · 10% owner

ARCH Venture Fund X Overage, L.P. · CIK 0001757017 · 10% owner

CRANDELL KEITH · CIK 0001219039 · 10% owner

Burow Kristina · CIK 0001569248 · 10% owner

GILLIS STEVEN · CIK 0001229592 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Indirect · By ARCH Venture Fund X Overage, L.P.

Disclosed balance after: 0

Underlying: Common Stock · 367,175 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F5 · derivative.exercise_price: Reflects shares purchased by ARCH X in the Issuer's initial public offering.

F5 · derivative.exercise_date: Reflects shares purchased by ARCH X in the Issuer's initial public offering.

F5 · derivative.expiration_date: Reflects shares purchased by ARCH X in the Issuer's initial public offering.

F3 · ownership.nature: ARCH Venture Partners X, LLC ("AVP X LLC") is the sole general partner of each of AVP X LP and AVP X Overage LP. Keith Crandell, Kristina Burow and Steven Gillis are members of the investment committee of AVP X LLC (the "AVP X Committee Members"). AVP X LP and AVP X Overage LP may be deemed to beneficially own the shares held by ARCH X and ARCH X Overage, respectively, AVP X LLC may be deemed to beneficially own the shares held by ARCH X and ARCH X Overage, and each of the AVP X Committee Members may be deemed to share the power to direct the disposition and vote of the shares held by ARCH X and ARCH X Overage. AVP X LP, AVP X Overage LP, AVP X LLC, and the AVP X Committee Members each disclaim beneficial ownership except to the extent of any pecuniary interest therein, and this report shall not be deemed an admission that such shares are beneficially owned by them for Section 16 or any other purpose.

F4 · ownership.nature: Represents shares held directly by ARCH Venture Fund X Overage, L.P. ("ARCH X Overage"). ARCH Venture Partners X Overage, L.P. ("AVP X Overage LP") is the sole general partner of ARCH X Overage.

SEC source: 0001628280-22-027125 · wf-form4_166682887797580.xml · derivative · entry 7

ARCH Venture Partners X, LLC · CIK 0001769012 · 10% owner

ARCH Venture Partners X, L.P. · CIK 0001782583 · 10% owner

ARCH Venture Partners X Overage, L.P. · CIK 0001768905 · 10% owner

ARCH Venture Fund X, L.P. · CIK 0001757011 · 10% owner

ARCH Venture Fund X Overage, L.P. · CIK 0001757017 · 10% owner

CRANDELL KEITH · CIK 0001219039 · 10% owner

Burow Kristina · CIK 0001569248 · 10% owner

GILLIS STEVEN · CIK 0001229592 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Indirect · By ARCH Venture Fund X, L.P.

Disclosed balance after: 0

Underlying: Common Stock · 367,175 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · derivative.exercise_price: The shares of Series A Convertible Preferred Stock and Series B Convertible Preferred Stock (together, the "Preferred Stock") were convertible into Common Stock on a one-for-3.10880 basis at any time at the option of the holder, and automatically converted into the number of shares shown in Column 7 immediately prior to the closing of the Issuer's initial public offering on October 24, 2022. The Preferred Stock had no expiration date.

F1 · derivative.exercise_date: The shares of Series A Convertible Preferred Stock and Series B Convertible Preferred Stock (together, the "Preferred Stock") were convertible into Common Stock on a one-for-3.10880 basis at any time at the option of the holder, and automatically converted into the number of shares shown in Column 7 immediately prior to the closing of the Issuer's initial public offering on October 24, 2022. The Preferred Stock had no expiration date.

F1 · derivative.expiration_date: The shares of Series A Convertible Preferred Stock and Series B Convertible Preferred Stock (together, the "Preferred Stock") were convertible into Common Stock on a one-for-3.10880 basis at any time at the option of the holder, and automatically converted into the number of shares shown in Column 7 immediately prior to the closing of the Issuer's initial public offering on October 24, 2022. The Preferred Stock had no expiration date.

F2 · ownership.nature: Represents shares held directly by ARCH Venture Fund X, L.P. ("ARCH X"). ARCH Venture Partners X, L.P. ("AVP X LP") is the sole general partner of ARCH X.

F3 · ownership.nature: ARCH Venture Partners X, LLC ("AVP X LLC") is the sole general partner of each of AVP X LP and AVP X Overage LP. Keith Crandell, Kristina Burow and Steven Gillis are members of the investment committee of AVP X LLC (the "AVP X Committee Members"). AVP X LP and AVP X Overage LP may be deemed to beneficially own the shares held by ARCH X and ARCH X Overage, respectively, AVP X LLC may be deemed to beneficially own the shares held by ARCH X and ARCH X Overage, and each of the AVP X Committee Members may be deemed to share the power to direct the disposition and vote of the shares held by ARCH X and ARCH X Overage. AVP X LP, AVP X Overage LP, AVP X LLC, and the AVP X Committee Members each disclaim beneficial ownership except to the extent of any pecuniary interest therein, and this report shall not be deemed an admission that such shares are beneficially owned by them for Section 16 or any other purpose.

SEC source: 0001628280-22-027125 · wf-form4_166682887797580.xml · derivative · entry 6

ARCH Venture Partners X, LLC · CIK 0001769012 · 10% owner

ARCH Venture Partners X, L.P. · CIK 0001782583 · 10% owner

ARCH Venture Partners X Overage, L.P. · CIK 0001768905 · 10% owner

ARCH Venture Fund X, L.P. · CIK 0001757011 · 10% owner

ARCH Venture Fund X Overage, L.P. · CIK 0001757017 · 10% owner

CRANDELL KEITH · CIK 0001219039 · 10% owner

Burow Kristina · CIK 0001569248 · 10% owner

GILLIS STEVEN · CIK 0001229592 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Indirect · By ARCH Venture Fund X Overage, L.P.

Disclosed balance after: 0

Underlying: Common Stock · 5,361,122 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · derivative.exercise_price: The shares of Series A Convertible Preferred Stock and Series B Convertible Preferred Stock (together, the "Preferred Stock") were convertible into Common Stock on a one-for-3.10880 basis at any time at the option of the holder, and automatically converted into the number of shares shown in Column 7 immediately prior to the closing of the Issuer's initial public offering on October 24, 2022. The Preferred Stock had no expiration date.

F1 · derivative.exercise_date: The shares of Series A Convertible Preferred Stock and Series B Convertible Preferred Stock (together, the "Preferred Stock") were convertible into Common Stock on a one-for-3.10880 basis at any time at the option of the holder, and automatically converted into the number of shares shown in Column 7 immediately prior to the closing of the Issuer's initial public offering on October 24, 2022. The Preferred Stock had no expiration date.

F1 · derivative.expiration_date: The shares of Series A Convertible Preferred Stock and Series B Convertible Preferred Stock (together, the "Preferred Stock") were convertible into Common Stock on a one-for-3.10880 basis at any time at the option of the holder, and automatically converted into the number of shares shown in Column 7 immediately prior to the closing of the Issuer's initial public offering on October 24, 2022. The Preferred Stock had no expiration date.

F3 · ownership.nature: ARCH Venture Partners X, LLC ("AVP X LLC") is the sole general partner of each of AVP X LP and AVP X Overage LP. Keith Crandell, Kristina Burow and Steven Gillis are members of the investment committee of AVP X LLC (the "AVP X Committee Members"). AVP X LP and AVP X Overage LP may be deemed to beneficially own the shares held by ARCH X and ARCH X Overage, respectively, AVP X LLC may be deemed to beneficially own the shares held by ARCH X and ARCH X Overage, and each of the AVP X Committee Members may be deemed to share the power to direct the disposition and vote of the shares held by ARCH X and ARCH X Overage. AVP X LP, AVP X Overage LP, AVP X LLC, and the AVP X Committee Members each disclaim beneficial ownership except to the extent of any pecuniary interest therein, and this report shall not be deemed an admission that such shares are beneficially owned by them for Section 16 or any other purpose.

F4 · ownership.nature: Represents shares held directly by ARCH Venture Fund X Overage, L.P. ("ARCH X Overage"). ARCH Venture Partners X Overage, L.P. ("AVP X Overage LP") is the sole general partner of ARCH X Overage.

SEC source: 0001628280-22-027125 · wf-form4_166682887797580.xml · derivative · entry 5

ARCH Venture Partners X, LLC · CIK 0001769012 · 10% owner

ARCH Venture Partners X, L.P. · CIK 0001782583 · 10% owner

ARCH Venture Partners X Overage, L.P. · CIK 0001768905 · 10% owner

ARCH Venture Fund X, L.P. · CIK 0001757011 · 10% owner

ARCH Venture Fund X Overage, L.P. · CIK 0001757017 · 10% owner

CRANDELL KEITH · CIK 0001219039 · 10% owner

Burow Kristina · CIK 0001569248 · 10% owner

GILLIS STEVEN · CIK 0001229592 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Indirect · By ARCH Venture Fund X, L.P

Disclosed balance after: 0

Underlying: Common Stock · 5,361,122 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · derivative.exercise_price: The shares of Series A Convertible Preferred Stock and Series B Convertible Preferred Stock (together, the "Preferred Stock") were convertible into Common Stock on a one-for-3.10880 basis at any time at the option of the holder, and automatically converted into the number of shares shown in Column 7 immediately prior to the closing of the Issuer's initial public offering on October 24, 2022. The Preferred Stock had no expiration date.

F1 · derivative.exercise_date: The shares of Series A Convertible Preferred Stock and Series B Convertible Preferred Stock (together, the "Preferred Stock") were convertible into Common Stock on a one-for-3.10880 basis at any time at the option of the holder, and automatically converted into the number of shares shown in Column 7 immediately prior to the closing of the Issuer's initial public offering on October 24, 2022. The Preferred Stock had no expiration date.

F1 · derivative.expiration_date: The shares of Series A Convertible Preferred Stock and Series B Convertible Preferred Stock (together, the "Preferred Stock") were convertible into Common Stock on a one-for-3.10880 basis at any time at the option of the holder, and automatically converted into the number of shares shown in Column 7 immediately prior to the closing of the Issuer's initial public offering on October 24, 2022. The Preferred Stock had no expiration date.

F2 · ownership.nature: Represents shares held directly by ARCH Venture Fund X, L.P. ("ARCH X"). ARCH Venture Partners X, L.P. ("AVP X LP") is the sole general partner of ARCH X.

F3 · ownership.nature: ARCH Venture Partners X, LLC ("AVP X LLC") is the sole general partner of each of AVP X LP and AVP X Overage LP. Keith Crandell, Kristina Burow and Steven Gillis are members of the investment committee of AVP X LLC (the "AVP X Committee Members"). AVP X LP and AVP X Overage LP may be deemed to beneficially own the shares held by ARCH X and ARCH X Overage, respectively, AVP X LLC may be deemed to beneficially own the shares held by ARCH X and ARCH X Overage, and each of the AVP X Committee Members may be deemed to share the power to direct the disposition and vote of the shares held by ARCH X and ARCH X Overage. AVP X LP, AVP X Overage LP, AVP X LLC, and the AVP X Committee Members each disclaim beneficial ownership except to the extent of any pecuniary interest therein, and this report shall not be deemed an admission that such shares are beneficially owned by them for Section 16 or any other purpose.

SEC source: 0001628280-22-027125 · wf-form4_166682887797580.xml · nonDerivative · entry 4

ARCH Venture Partners X, LLC · CIK 0001769012 · 10% owner

ARCH Venture Partners X, L.P. · CIK 0001782583 · 10% owner

ARCH Venture Partners X Overage, L.P. · CIK 0001768905 · 10% owner

ARCH Venture Fund X, L.P. · CIK 0001757011 · 10% owner

ARCH Venture Fund X Overage, L.P. · CIK 0001757017 · 10% owner

CRANDELL KEITH · CIK 0001219039 · 10% owner

Burow Kristina · CIK 0001569248 · 10% owner

GILLIS STEVEN · CIK 0001229592 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Indirect · By ARCH Venture Fund X Overage, L.P.

Disclosed balance after: 6,128,297

F2 · ownership.nature: Represents shares held directly by ARCH Venture Fund X, L.P. ("ARCH X"). ARCH Venture Partners X, L.P. ("AVP X LP") is the sole general partner of ARCH X.

F3 · ownership.nature: ARCH Venture Partners X, LLC ("AVP X LLC") is the sole general partner of each of AVP X LP and AVP X Overage LP. Keith Crandell, Kristina Burow and Steven Gillis are members of the investment committee of AVP X LLC (the "AVP X Committee Members"). AVP X LP and AVP X Overage LP may be deemed to beneficially own the shares held by ARCH X and ARCH X Overage, respectively, AVP X LLC may be deemed to beneficially own the shares held by ARCH X and ARCH X Overage, and each of the AVP X Committee Members may be deemed to share the power to direct the disposition and vote of the shares held by ARCH X and ARCH X Overage. AVP X LP, AVP X Overage LP, AVP X LLC, and the AVP X Committee Members each disclaim beneficial ownership except to the extent of any pecuniary interest therein, and this report shall not be deemed an admission that such shares are beneficially owned by them for Section 16 or any other purpose.

F6 · ownership.nature: Reflects shares purchased by ARCH X Overage in the Issuer's initial public offering.

SEC source: 0001628280-22-027125 · wf-form4_166682887797580.xml · nonDerivative · entry 3

ARCH Venture Partners X, LLC · CIK 0001769012 · 10% owner

ARCH Venture Partners X, L.P. · CIK 0001782583 · 10% owner

ARCH Venture Partners X Overage, L.P. · CIK 0001768905 · 10% owner

ARCH Venture Fund X, L.P. · CIK 0001757011 · 10% owner

ARCH Venture Fund X Overage, L.P. · CIK 0001757017 · 10% owner

CRANDELL KEITH · CIK 0001219039 · 10% owner

Burow Kristina · CIK 0001569248 · 10% owner

GILLIS STEVEN · CIK 0001229592 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Indirect · By ARCH Venture Fund X, L.P.

Disclosed balance after: 6,128,297

F2 · ownership.nature: Represents shares held directly by ARCH Venture Fund X, L.P. ("ARCH X"). ARCH Venture Partners X, L.P. ("AVP X LP") is the sole general partner of ARCH X.

F3 · ownership.nature: ARCH Venture Partners X, LLC ("AVP X LLC") is the sole general partner of each of AVP X LP and AVP X Overage LP. Keith Crandell, Kristina Burow and Steven Gillis are members of the investment committee of AVP X LLC (the "AVP X Committee Members"). AVP X LP and AVP X Overage LP may be deemed to beneficially own the shares held by ARCH X and ARCH X Overage, respectively, AVP X LLC may be deemed to beneficially own the shares held by ARCH X and ARCH X Overage, and each of the AVP X Committee Members may be deemed to share the power to direct the disposition and vote of the shares held by ARCH X and ARCH X Overage. AVP X LP, AVP X Overage LP, AVP X LLC, and the AVP X Committee Members each disclaim beneficial ownership except to the extent of any pecuniary interest therein, and this report shall not be deemed an admission that such shares are beneficially owned by them for Section 16 or any other purpose.

F5 · ownership.nature: Reflects shares purchased by ARCH X in the Issuer's initial public offering.

SEC source: 0001628280-22-027125 · wf-form4_166682887797580.xml · nonDerivative · entry 2

ARCH Venture Partners X, LLC · CIK 0001769012 · 10% owner

ARCH Venture Partners X, L.P. · CIK 0001782583 · 10% owner

ARCH Venture Partners X Overage, L.P. · CIK 0001768905 · 10% owner

ARCH Venture Fund X, L.P. · CIK 0001757011 · 10% owner

ARCH Venture Fund X Overage, L.P. · CIK 0001757017 · 10% owner

CRANDELL KEITH · CIK 0001219039 · 10% owner

Burow Kristina · CIK 0001569248 · 10% owner

GILLIS STEVEN · CIK 0001229592 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Indirect · By ARCH Venture Fund X Overage, L.P.

Disclosed balance after: 5,728,297

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · price: The shares of Series A Convertible Preferred Stock and Series B Convertible Preferred Stock (together, the "Preferred Stock") were convertible into Common Stock on a one-for-3.10880 basis at any time at the option of the holder, and automatically converted into the number of shares shown in Column 7 immediately prior to the closing of the Issuer's initial public offering on October 24, 2022. The Preferred Stock had no expiration date.

F3 · ownership.nature: ARCH Venture Partners X, LLC ("AVP X LLC") is the sole general partner of each of AVP X LP and AVP X Overage LP. Keith Crandell, Kristina Burow and Steven Gillis are members of the investment committee of AVP X LLC (the "AVP X Committee Members"). AVP X LP and AVP X Overage LP may be deemed to beneficially own the shares held by ARCH X and ARCH X Overage, respectively, AVP X LLC may be deemed to beneficially own the shares held by ARCH X and ARCH X Overage, and each of the AVP X Committee Members may be deemed to share the power to direct the disposition and vote of the shares held by ARCH X and ARCH X Overage. AVP X LP, AVP X Overage LP, AVP X LLC, and the AVP X Committee Members each disclaim beneficial ownership except to the extent of any pecuniary interest therein, and this report shall not be deemed an admission that such shares are beneficially owned by them for Section 16 or any other purpose.

F4 · ownership.nature: Represents shares held directly by ARCH Venture Fund X Overage, L.P. ("ARCH X Overage"). ARCH Venture Partners X Overage, L.P. ("AVP X Overage LP") is the sole general partner of ARCH X Overage.

SEC source: 0001628280-22-027125 · wf-form4_166682887797580.xml · nonDerivative · entry 1

ARCH Venture Partners X, LLC · CIK 0001769012 · 10% owner

ARCH Venture Partners X, L.P. · CIK 0001782583 · 10% owner

ARCH Venture Partners X Overage, L.P. · CIK 0001768905 · 10% owner

ARCH Venture Fund X, L.P. · CIK 0001757011 · 10% owner

ARCH Venture Fund X Overage, L.P. · CIK 0001757017 · 10% owner

CRANDELL KEITH · CIK 0001219039 · 10% owner

Burow Kristina · CIK 0001569248 · 10% owner

GILLIS STEVEN · CIK 0001229592 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Indirect · By ARCH Venture Fund X, L.P.

Disclosed balance after: 5,728,297

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · price: The shares of Series A Convertible Preferred Stock and Series B Convertible Preferred Stock (together, the "Preferred Stock") were convertible into Common Stock on a one-for-3.10880 basis at any time at the option of the holder, and automatically converted into the number of shares shown in Column 7 immediately prior to the closing of the Issuer's initial public offering on October 24, 2022. The Preferred Stock had no expiration date.

F2 · ownership.nature: Represents shares held directly by ARCH Venture Fund X, L.P. ("ARCH X"). ARCH Venture Partners X, L.P. ("AVP X LP") is the sole general partner of ARCH X.

F3 · ownership.nature: ARCH Venture Partners X, LLC ("AVP X LLC") is the sole general partner of each of AVP X LP and AVP X Overage LP. Keith Crandell, Kristina Burow and Steven Gillis are members of the investment committee of AVP X LLC (the "AVP X Committee Members"). AVP X LP and AVP X Overage LP may be deemed to beneficially own the shares held by ARCH X and ARCH X Overage, respectively, AVP X LLC may be deemed to beneficially own the shares held by ARCH X and ARCH X Overage, and each of the AVP X Committee Members may be deemed to share the power to direct the disposition and vote of the shares held by ARCH X and ARCH X Overage. AVP X LP, AVP X Overage LP, AVP X LLC, and the AVP X Committee Members each disclaim beneficial ownership except to the extent of any pecuniary interest therein, and this report shall not be deemed an admission that such shares are beneficially owned by them for Section 16 or any other purpose.

SEC source: 0000899243-22-030277 · doc4.xml · derivative · entry 1

Burow Kristina · CIK 0001569248 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 10,391

Underlying: Common Stock · 10,391 shares

Expires 2032-09-01

F1 · derivative.exercise_date: The option vests in full on the first anniversary of the date of grant, subject to the reporting person's continued service to the board of directors of Beam Therapeutics Inc. through the vesting date.

SEC source: 0001728117-22-000078 · wf-form4_165792005588771.xml · derivative · entry 1

Burow Kristina · CIK 0001569248 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 30,000

Underlying: Common Stock · 30,000 shares

Expires 2032-06-08

F1 · kind: Award made pursuant to Non-Employee Director Compensation Program.

F2 · derivative.exercise_date: The entire number of shares subject to this option becomes fully vested and exercisable on the first to occur of (a) the first anniversary of the grant date or (b) the next occurring annual meeting of the Issuer'sstockholders, subject to the Reporting Person's continued service on the board of directors of the Issuer through such vesting date.

SEC source: 0001104659-22-065950 · tm2216969-3_4seq1.xml · derivative · entry 1

Burow Kristina · CIK 0001569248 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 28,000

Underlying: Common Stock · 28,000 shares

Expires 2032-05-26

F1 · derivative.exercise_date: This option shall vest and become fully exercisable on the earlier of the first anniversary following the date of grant or the next scheduled Annual Meeting subject to continued service to the Issuer through such date.

SEC source: 0000899243-21-032264 · doc4.xml · derivative · entry 1

ARCH Venture Fund XI, L.P. · CIK 0001831802 · 10% owner · Member of 10% owner group

ARCH Venture Partners XI, L.P. · CIK 0001847567 · 10% owner

ARCH Venture Partners XI, LLC · CIK 0001847601 · 10% owner

NELSEN ROBERT · CIK 0001219042 · 10% owner

Burow Kristina · CIK 0001569248 · 10% owner

GILLIS STEVEN · CIK 0001229592 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Indirect · Through DA32 Sponsor LLC

Disclosed balance after: 4,465,000

Underlying: Class A Common Stock · 701,250 shares

Expires not disclosed

F1 · derivative.exercise_price: The shares of Class B Common Stock are convertible into shares of the Issuer's Class A Common Stock as described under the heading "Description of Shares" in the Issuer's Registration Statement on Form S-1 (File No. 333-257679) (the "Registration Statement") and have no expiration date.

F2 · kind: On August 5, 2021, DA32 Sponsor LLC ("Sponsor") forfeited 701,250 shares of Class B Common Stock to the Issuer for no consideration in connection with the underwriters' election to forfeit their overallotment option on August 4, 2021. The forfeiture was not within the Reporting Persons' control as it occurred exclusively due to the underwriters' decision not to exercise the overallotment option and occurred shortly after the Issuer filed the final statutory prospectus for the initial public offering (the "IPO") disclosing all material information about the Issuer and the IPO.

F1 · derivative.exercise_date: The shares of Class B Common Stock are convertible into shares of the Issuer's Class A Common Stock as described under the heading "Description of Shares" in the Issuer's Registration Statement on Form S-1 (File No. 333-257679) (the "Registration Statement") and have no expiration date.

F1 · derivative.expiration_date: The shares of Class B Common Stock are convertible into shares of the Issuer's Class A Common Stock as described under the heading "Description of Shares" in the Issuer's Registration Statement on Form S-1 (File No. 333-257679) (the "Registration Statement") and have no expiration date.

F2 · derivative.underlying_shares: On August 5, 2021, DA32 Sponsor LLC ("Sponsor") forfeited 701,250 shares of Class B Common Stock to the Issuer for no consideration in connection with the underwriters' election to forfeit their overallotment option on August 4, 2021. The forfeiture was not within the Reporting Persons' control as it occurred exclusively due to the underwriters' decision not to exercise the overallotment option and occurred shortly after the Issuer filed the final statutory prospectus for the initial public offering (the "IPO") disclosing all material information about the Issuer and the IPO.

F3 · ownership.nature: This Form 4 is filed jointly by ARCH Venture Fund XI, L.P. ("AVF"), ARCH Venture Partners XI, L.P. ("AVP LP"), ARCH Venture Partners XI, LLC ("AVP LLC"), Kristina Burow, Robert Nelsen and Steven Gillis (collectively, the "Reporting Persons"). Keith Crandell has direct ownership of the Issuer's Class B Common Stock, as well as indirect pecuniary ownership of the Issuer's Class A Common Stock and Class B Common Stock and is filing his own Form 4 separately. Burow, Crandell, Nelsen and Gillis comprise the investment committee of AVP LLC (the AVP X Committee Members). Each of the Reporting Persons is a member of a Section 13(d) group. Each of the Reporting Persons disclaims beneficial ownership of the securities reported herein except to the extent of such Reporting Person's pecuniary interest therein.

F4 · ownership.nature: As a managing member of Sponsor, AVF may be deemed to beneficially own the securities owned directly by Sponsor. As the sole general partner of AVF, AVP LP may be deemed to beneficially own the securities owned directly by Sponsor. As the sole general partner of AVP LP, AVP LLC may be deemed to beneficially own securities owned directly by Sponsor. As the members of the investment committee, each of the AVP X Committee Members may be deemed to beneficially own securities owned directly by Sponsor. Each of the Reporting Persons disclaims beneficial ownership of the securities reported herein except to the extent of such Reporting Person's pecuniary interest therein.

SEC source: 0000899243-21-031417 · doc4.xml · nonDerivative · entry 2

ARCH Venture Fund XI, L.P. · CIK 0001831802 · 10% owner

ARCH Venture Partners XI, L.P. · CIK 0001847567 · 10% owner

ARCH Venture Partners XI, LLC · CIK 0001847601 · 10% owner

NELSEN ROBERT · CIK 0001219042 · 10% owner

Burow Kristina · CIK 0001569248 · 10% owner

GILLIS STEVEN · CIK 0001229592 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Indirect · Through A32 ponsor LC

Disclosed balance after: 2,250,000

F4 · security: As a managing member of Sponsor, AVF may be deemed to beneficially own the securities owned directly by Sponsor. As the sole general partner of AVF, AVP LP may be deemed to beneficially own the securities owned directly by Sponsor. As the sole general partner of AVP LP, AVP LLC may be deemed to beneficially own securities owned directly by Sponsor. As the members of the investment committee, each of the AVP X Committee Members may be deemed to beneficially own securities owned directly by Sponsor. Each of the Reporting Persons disclaims beneficial ownership of the securities reported herein except to the extent of such Reporting Person's pecuniary interest therein.

F3 · kind: DA32 Sponsor LLC ("Sponsor") purchased 650,000 shares of Class A common stock directly from the Issuer in a private placement for $10.00 per share, concurrently with the Issuer's initial public offering.

F3 · shares: DA32 Sponsor LLC ("Sponsor") purchased 650,000 shares of Class A common stock directly from the Issuer in a private placement for $10.00 per share, concurrently with the Issuer's initial public offering.

F2 · ownership.nature: This Form 4 is filed jointly by ARCH Venture Fund XI, L.P. ("AVF"), ARCH Venture Partners XI, L.P. ("AVP LP"), ARCH Venture Partners XI, LLC ("AVP LLC"), Kristina Burow, Robert Nelsen and Steven Gillis (collectively, the "Reporting Persons"). Keith Crandell has direct ownership of the Issuer's Class B Common Stock, as well as indirect pecuniary ownership of the Issuer's Class A common stock and Class B Common Stock and is filing his own Form 4 separately. Burow, Crandell, Nelsen and Gillis comprise the investment committee of AVP LLC (the AVP X Committee Members). Each of the Reporting Persons is a member of a Section 13(d) group. Each of the Reporting Persons disclaims beneficial ownership of the securities reported herein except to the extent of such Reporting Person's pecuniary interest therein.

F4 · ownership.nature: As a managing member of Sponsor, AVF may be deemed to beneficially own the securities owned directly by Sponsor. As the sole general partner of AVF, AVP LP may be deemed to beneficially own the securities owned directly by Sponsor. As the sole general partner of AVP LP, AVP LLC may be deemed to beneficially own securities owned directly by Sponsor. As the members of the investment committee, each of the AVP X Committee Members may be deemed to beneficially own securities owned directly by Sponsor. Each of the Reporting Persons disclaims beneficial ownership of the securities reported herein except to the extent of such Reporting Person's pecuniary interest therein.

SEC source: 0000899243-21-031417 · doc4.xml · nonDerivative · entry 1

ARCH Venture Fund XI, L.P. · CIK 0001831802 · 10% owner

ARCH Venture Partners XI, L.P. · CIK 0001847567 · 10% owner

ARCH Venture Partners XI, LLC · CIK 0001847601 · 10% owner

NELSEN ROBERT · CIK 0001219042 · 10% owner

Burow Kristina · CIK 0001569248 · 10% owner

GILLIS STEVEN · CIK 0001229592 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 1,600,000

F1 · kind: ARCH Venture Fund XI, L.P. purchased 1,600,000 shares of the Issuer's Class A common stock for $10.00 per share in the Issuer's initial public offering.

F2 · ownership.direct: This Form 4 is filed jointly by ARCH Venture Fund XI, L.P. ("AVF"), ARCH Venture Partners XI, L.P. ("AVP LP"), ARCH Venture Partners XI, LLC ("AVP LLC"), Kristina Burow, Robert Nelsen and Steven Gillis (collectively, the "Reporting Persons"). Keith Crandell has direct ownership of the Issuer's Class B Common Stock, as well as indirect pecuniary ownership of the Issuer's Class A common stock and Class B Common Stock and is filing his own Form 4 separately. Burow, Crandell, Nelsen and Gillis comprise the investment committee of AVP LLC (the AVP X Committee Members). Each of the Reporting Persons is a member of a Section 13(d) group. Each of the Reporting Persons disclaims beneficial ownership of the securities reported herein except to the extent of such Reporting Person's pecuniary interest therein.

SEC source: 0000899243-21-029077 · doc4.xml · derivative · entry 8

ARCH Venture Partners X, LLC · CIK 0001769012 · 10% owner

ARCH Venture Fund X, L.P. · CIK 0001757011 · 10% owner

ARCH Venture Fund X Overage, L.P. · CIK 0001757017 · 10% owner

ARCH Venture Partners X, L.P. · CIK 0001782583 · 10% owner

ARCH Venture Partners X Overage, L.P. · CIK 0001768905 · 10% owner

NELSEN ROBERT · CIK 0001219042 · 10% owner

CRANDELL KEITH · CIK 0001219039 · 10% owner

Burow Kristina · CIK 0001569248 · 10% owner

GILLIS STEVEN · CIK 0001229592 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Indirect · By ARCH Venture Fund X Overage, L.P.

Disclosed balance after: 0

Underlying: Common Stock · 944,444 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · price: The shares of the Issuer's Series A and Series B Preferred Stock automatically converted into shares of the Issuer's Common Stock, for no additional consideration, at a ratio of 1.2-for-1 share, immediately prior to the consummation of the Issuer's initial public offering.

F1 · derivative.exercise_date: The shares of the Issuer's Series A and Series B Preferred Stock automatically converted into shares of the Issuer's Common Stock, for no additional consideration, at a ratio of 1.2-for-1 share, immediately prior to the consummation of the Issuer's initial public offering.

F1 · derivative.expiration_date: The shares of the Issuer's Series A and Series B Preferred Stock automatically converted into shares of the Issuer's Common Stock, for no additional consideration, at a ratio of 1.2-for-1 share, immediately prior to the consummation of the Issuer's initial public offering.

F2 · ownership.nature: ARCH Venture Partners X, L.P. (AVP X LP) is the sole general partner of ARCH Venture Fund X, L.P. (ARCH X). ARCH Venture Partners X Overage, L.P. (AVP X Overage LP) is the sole general partner of ARCH Venture Fund X Overage, L.P. (ARCH X Overage). ARCH Venture Partners X, LLC (AVP X LLC) is the sole general partner of each of AVP X LP and AVP X Overage LP. Keith Crandell, Kristina Burow, Steven Gillis, and Robert Nelsen comprise the investment committee of AVP X LLC (the AVP X Committee Members). AVP X LP and AVP X Overage LP may be deemed to beneficially own the shares held by ARCH X and ARCH X Overage, respectively, AVP X LLC may be deemed to beneficially own the shares held by ARCH X and ARCH X Overage, and each of the AVP X Committee Members may be deemed to share the power to direct the disposition and vote of the shares held by ARCH X and ARCH X Overage.

F3 · ownership.nature: (Continued from Footnote 2) AVP X LP, AVP X Overage LP, AVP X LLC, and the AVP X Committee Members each disclaim beneficial ownership except to any pecuniary interest therein.

SEC source: 0000899243-21-029077 · doc4.xml · derivative · entry 7

ARCH Venture Partners X, LLC · CIK 0001769012 · 10% owner

ARCH Venture Fund X, L.P. · CIK 0001757011 · 10% owner

ARCH Venture Fund X Overage, L.P. · CIK 0001757017 · 10% owner

ARCH Venture Partners X, L.P. · CIK 0001782583 · 10% owner

ARCH Venture Partners X Overage, L.P. · CIK 0001768905 · 10% owner

NELSEN ROBERT · CIK 0001219042 · 10% owner

CRANDELL KEITH · CIK 0001219039 · 10% owner

Burow Kristina · CIK 0001569248 · 10% owner

GILLIS STEVEN · CIK 0001229592 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Indirect · By ARCH Venture Fund X Overage, L.P.

Disclosed balance after: 0

Underlying: Common Stock · 2,833,333 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · price: The shares of the Issuer's Series A and Series B Preferred Stock automatically converted into shares of the Issuer's Common Stock, for no additional consideration, at a ratio of 1.2-for-1 share, immediately prior to the consummation of the Issuer's initial public offering.

F1 · derivative.exercise_date: The shares of the Issuer's Series A and Series B Preferred Stock automatically converted into shares of the Issuer's Common Stock, for no additional consideration, at a ratio of 1.2-for-1 share, immediately prior to the consummation of the Issuer's initial public offering.

F1 · derivative.expiration_date: The shares of the Issuer's Series A and Series B Preferred Stock automatically converted into shares of the Issuer's Common Stock, for no additional consideration, at a ratio of 1.2-for-1 share, immediately prior to the consummation of the Issuer's initial public offering.

F2 · ownership.nature: ARCH Venture Partners X, L.P. (AVP X LP) is the sole general partner of ARCH Venture Fund X, L.P. (ARCH X). ARCH Venture Partners X Overage, L.P. (AVP X Overage LP) is the sole general partner of ARCH Venture Fund X Overage, L.P. (ARCH X Overage). ARCH Venture Partners X, LLC (AVP X LLC) is the sole general partner of each of AVP X LP and AVP X Overage LP. Keith Crandell, Kristina Burow, Steven Gillis, and Robert Nelsen comprise the investment committee of AVP X LLC (the AVP X Committee Members). AVP X LP and AVP X Overage LP may be deemed to beneficially own the shares held by ARCH X and ARCH X Overage, respectively, AVP X LLC may be deemed to beneficially own the shares held by ARCH X and ARCH X Overage, and each of the AVP X Committee Members may be deemed to share the power to direct the disposition and vote of the shares held by ARCH X and ARCH X Overage.

F3 · ownership.nature: (Continued from Footnote 2) AVP X LP, AVP X Overage LP, AVP X LLC, and the AVP X Committee Members each disclaim beneficial ownership except to any pecuniary interest therein.

SEC source: 0000899243-21-029077 · doc4.xml · derivative · entry 6

ARCH Venture Partners X, LLC · CIK 0001769012 · 10% owner

ARCH Venture Fund X, L.P. · CIK 0001757011 · 10% owner

ARCH Venture Fund X Overage, L.P. · CIK 0001757017 · 10% owner

ARCH Venture Partners X, L.P. · CIK 0001782583 · 10% owner

ARCH Venture Partners X Overage, L.P. · CIK 0001768905 · 10% owner

NELSEN ROBERT · CIK 0001219042 · 10% owner

CRANDELL KEITH · CIK 0001219039 · 10% owner

Burow Kristina · CIK 0001569248 · 10% owner

GILLIS STEVEN · CIK 0001229592 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Indirect · By ARCH Venture Fund X, L.P.

Disclosed balance after: 0

Underlying: Common Stock · 944,444 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · price: The shares of the Issuer's Series A and Series B Preferred Stock automatically converted into shares of the Issuer's Common Stock, for no additional consideration, at a ratio of 1.2-for-1 share, immediately prior to the consummation of the Issuer's initial public offering.

F1 · derivative.exercise_date: The shares of the Issuer's Series A and Series B Preferred Stock automatically converted into shares of the Issuer's Common Stock, for no additional consideration, at a ratio of 1.2-for-1 share, immediately prior to the consummation of the Issuer's initial public offering.

F1 · derivative.expiration_date: The shares of the Issuer's Series A and Series B Preferred Stock automatically converted into shares of the Issuer's Common Stock, for no additional consideration, at a ratio of 1.2-for-1 share, immediately prior to the consummation of the Issuer's initial public offering.

F2 · ownership.nature: ARCH Venture Partners X, L.P. (AVP X LP) is the sole general partner of ARCH Venture Fund X, L.P. (ARCH X). ARCH Venture Partners X Overage, L.P. (AVP X Overage LP) is the sole general partner of ARCH Venture Fund X Overage, L.P. (ARCH X Overage). ARCH Venture Partners X, LLC (AVP X LLC) is the sole general partner of each of AVP X LP and AVP X Overage LP. Keith Crandell, Kristina Burow, Steven Gillis, and Robert Nelsen comprise the investment committee of AVP X LLC (the AVP X Committee Members). AVP X LP and AVP X Overage LP may be deemed to beneficially own the shares held by ARCH X and ARCH X Overage, respectively, AVP X LLC may be deemed to beneficially own the shares held by ARCH X and ARCH X Overage, and each of the AVP X Committee Members may be deemed to share the power to direct the disposition and vote of the shares held by ARCH X and ARCH X Overage.

F3 · ownership.nature: (Continued from Footnote 2) AVP X LP, AVP X Overage LP, AVP X LLC, and the AVP X Committee Members each disclaim beneficial ownership except to any pecuniary interest therein.

SEC source: 0000899243-21-029077 · doc4.xml · derivative · entry 5

ARCH Venture Partners X, LLC · CIK 0001769012 · 10% owner

ARCH Venture Fund X, L.P. · CIK 0001757011 · 10% owner

ARCH Venture Fund X Overage, L.P. · CIK 0001757017 · 10% owner

ARCH Venture Partners X, L.P. · CIK 0001782583 · 10% owner

ARCH Venture Partners X Overage, L.P. · CIK 0001768905 · 10% owner

NELSEN ROBERT · CIK 0001219042 · 10% owner

CRANDELL KEITH · CIK 0001219039 · 10% owner

Burow Kristina · CIK 0001569248 · 10% owner

GILLIS STEVEN · CIK 0001229592 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Indirect · By ARCH Venture Fund X, L.P.

Disclosed balance after: 0

Underlying: Common Stock · 2,833,333 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · price: The shares of the Issuer's Series A and Series B Preferred Stock automatically converted into shares of the Issuer's Common Stock, for no additional consideration, at a ratio of 1.2-for-1 share, immediately prior to the consummation of the Issuer's initial public offering.

F1 · derivative.exercise_date: The shares of the Issuer's Series A and Series B Preferred Stock automatically converted into shares of the Issuer's Common Stock, for no additional consideration, at a ratio of 1.2-for-1 share, immediately prior to the consummation of the Issuer's initial public offering.

F1 · derivative.expiration_date: The shares of the Issuer's Series A and Series B Preferred Stock automatically converted into shares of the Issuer's Common Stock, for no additional consideration, at a ratio of 1.2-for-1 share, immediately prior to the consummation of the Issuer's initial public offering.

F2 · ownership.nature: ARCH Venture Partners X, L.P. (AVP X LP) is the sole general partner of ARCH Venture Fund X, L.P. (ARCH X). ARCH Venture Partners X Overage, L.P. (AVP X Overage LP) is the sole general partner of ARCH Venture Fund X Overage, L.P. (ARCH X Overage). ARCH Venture Partners X, LLC (AVP X LLC) is the sole general partner of each of AVP X LP and AVP X Overage LP. Keith Crandell, Kristina Burow, Steven Gillis, and Robert Nelsen comprise the investment committee of AVP X LLC (the AVP X Committee Members). AVP X LP and AVP X Overage LP may be deemed to beneficially own the shares held by ARCH X and ARCH X Overage, respectively, AVP X LLC may be deemed to beneficially own the shares held by ARCH X and ARCH X Overage, and each of the AVP X Committee Members may be deemed to share the power to direct the disposition and vote of the shares held by ARCH X and ARCH X Overage.

F3 · ownership.nature: (Continued from Footnote 2) AVP X LP, AVP X Overage LP, AVP X LLC, and the AVP X Committee Members each disclaim beneficial ownership except to any pecuniary interest therein.

SEC source: 0000899243-21-029077 · doc4.xml · derivative · entry 4

ARCH Venture Partners X, LLC · CIK 0001769012 · 10% owner

ARCH Venture Fund X, L.P. · CIK 0001757011 · 10% owner

ARCH Venture Fund X Overage, L.P. · CIK 0001757017 · 10% owner

ARCH Venture Partners X, L.P. · CIK 0001782583 · 10% owner

ARCH Venture Partners X Overage, L.P. · CIK 0001768905 · 10% owner

NELSEN ROBERT · CIK 0001219042 · 10% owner

CRANDELL KEITH · CIK 0001219039 · 10% owner

Burow Kristina · CIK 0001569248 · 10% owner

GILLIS STEVEN · CIK 0001229592 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Indirect · By ARCH Venture Fund X Overage, L.P.

Disclosed balance after: 0

Underlying: Common Stock · 1,750,000 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · price: The shares of the Issuer's Series A and Series B Preferred Stock automatically converted into shares of the Issuer's Common Stock, for no additional consideration, at a ratio of 1.2-for-1 share, immediately prior to the consummation of the Issuer's initial public offering.

F1 · derivative.exercise_date: The shares of the Issuer's Series A and Series B Preferred Stock automatically converted into shares of the Issuer's Common Stock, for no additional consideration, at a ratio of 1.2-for-1 share, immediately prior to the consummation of the Issuer's initial public offering.

F1 · derivative.expiration_date: The shares of the Issuer's Series A and Series B Preferred Stock automatically converted into shares of the Issuer's Common Stock, for no additional consideration, at a ratio of 1.2-for-1 share, immediately prior to the consummation of the Issuer's initial public offering.

F2 · ownership.nature: ARCH Venture Partners X, L.P. (AVP X LP) is the sole general partner of ARCH Venture Fund X, L.P. (ARCH X). ARCH Venture Partners X Overage, L.P. (AVP X Overage LP) is the sole general partner of ARCH Venture Fund X Overage, L.P. (ARCH X Overage). ARCH Venture Partners X, LLC (AVP X LLC) is the sole general partner of each of AVP X LP and AVP X Overage LP. Keith Crandell, Kristina Burow, Steven Gillis, and Robert Nelsen comprise the investment committee of AVP X LLC (the AVP X Committee Members). AVP X LP and AVP X Overage LP may be deemed to beneficially own the shares held by ARCH X and ARCH X Overage, respectively, AVP X LLC may be deemed to beneficially own the shares held by ARCH X and ARCH X Overage, and each of the AVP X Committee Members may be deemed to share the power to direct the disposition and vote of the shares held by ARCH X and ARCH X Overage.

F3 · ownership.nature: (Continued from Footnote 2) AVP X LP, AVP X Overage LP, AVP X LLC, and the AVP X Committee Members each disclaim beneficial ownership except to any pecuniary interest therein.

SEC source: 0000899243-21-029077 · doc4.xml · derivative · entry 3

ARCH Venture Partners X, LLC · CIK 0001769012 · 10% owner

ARCH Venture Fund X, L.P. · CIK 0001757011 · 10% owner

ARCH Venture Fund X Overage, L.P. · CIK 0001757017 · 10% owner

ARCH Venture Partners X, L.P. · CIK 0001782583 · 10% owner

ARCH Venture Partners X Overage, L.P. · CIK 0001768905 · 10% owner

NELSEN ROBERT · CIK 0001219042 · 10% owner

CRANDELL KEITH · CIK 0001219039 · 10% owner

Burow Kristina · CIK 0001569248 · 10% owner

GILLIS STEVEN · CIK 0001229592 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Indirect · By ARCH Venture Fund X, L.P.

Disclosed balance after: 0

Underlying: Common Stock · 1,750,000 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · price: The shares of the Issuer's Series A and Series B Preferred Stock automatically converted into shares of the Issuer's Common Stock, for no additional consideration, at a ratio of 1.2-for-1 share, immediately prior to the consummation of the Issuer's initial public offering.

F1 · derivative.exercise_date: The shares of the Issuer's Series A and Series B Preferred Stock automatically converted into shares of the Issuer's Common Stock, for no additional consideration, at a ratio of 1.2-for-1 share, immediately prior to the consummation of the Issuer's initial public offering.

F1 · derivative.expiration_date: The shares of the Issuer's Series A and Series B Preferred Stock automatically converted into shares of the Issuer's Common Stock, for no additional consideration, at a ratio of 1.2-for-1 share, immediately prior to the consummation of the Issuer's initial public offering.

F2 · ownership.nature: ARCH Venture Partners X, L.P. (AVP X LP) is the sole general partner of ARCH Venture Fund X, L.P. (ARCH X). ARCH Venture Partners X Overage, L.P. (AVP X Overage LP) is the sole general partner of ARCH Venture Fund X Overage, L.P. (ARCH X Overage). ARCH Venture Partners X, LLC (AVP X LLC) is the sole general partner of each of AVP X LP and AVP X Overage LP. Keith Crandell, Kristina Burow, Steven Gillis, and Robert Nelsen comprise the investment committee of AVP X LLC (the AVP X Committee Members). AVP X LP and AVP X Overage LP may be deemed to beneficially own the shares held by ARCH X and ARCH X Overage, respectively, AVP X LLC may be deemed to beneficially own the shares held by ARCH X and ARCH X Overage, and each of the AVP X Committee Members may be deemed to share the power to direct the disposition and vote of the shares held by ARCH X and ARCH X Overage.

F3 · ownership.nature: (Continued from Footnote 2) AVP X LP, AVP X Overage LP, AVP X LLC, and the AVP X Committee Members each disclaim beneficial ownership except to any pecuniary interest therein.

SEC source: 0000899243-21-029077 · doc4.xml · nonDerivative · entry 2

ARCH Venture Partners X, LLC · CIK 0001769012 · 10% owner

ARCH Venture Fund X, L.P. · CIK 0001757011 · 10% owner

ARCH Venture Fund X Overage, L.P. · CIK 0001757017 · 10% owner

ARCH Venture Partners X, L.P. · CIK 0001782583 · 10% owner

ARCH Venture Partners X Overage, L.P. · CIK 0001768905 · 10% owner

NELSEN ROBERT · CIK 0001219042 · 10% owner

CRANDELL KEITH · CIK 0001219039 · 10% owner

Burow Kristina · CIK 0001569248 · 10% owner

GILLIS STEVEN · CIK 0001229592 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Indirect · By ARCH Venture Fund X Overage, L.P.

Disclosed balance after: 5,527,777

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · price: The shares of the Issuer's Series A and Series B Preferred Stock automatically converted into shares of the Issuer's Common Stock, for no additional consideration, at a ratio of 1.2-for-1 share, immediately prior to the consummation of the Issuer's initial public offering.

F2 · ownership.nature: ARCH Venture Partners X, L.P. (AVP X LP) is the sole general partner of ARCH Venture Fund X, L.P. (ARCH X). ARCH Venture Partners X Overage, L.P. (AVP X Overage LP) is the sole general partner of ARCH Venture Fund X Overage, L.P. (ARCH X Overage). ARCH Venture Partners X, LLC (AVP X LLC) is the sole general partner of each of AVP X LP and AVP X Overage LP. Keith Crandell, Kristina Burow, Steven Gillis, and Robert Nelsen comprise the investment committee of AVP X LLC (the AVP X Committee Members). AVP X LP and AVP X Overage LP may be deemed to beneficially own the shares held by ARCH X and ARCH X Overage, respectively, AVP X LLC may be deemed to beneficially own the shares held by ARCH X and ARCH X Overage, and each of the AVP X Committee Members may be deemed to share the power to direct the disposition and vote of the shares held by ARCH X and ARCH X Overage.

F3 · ownership.nature: (Continued from Footnote 2) AVP X LP, AVP X Overage LP, AVP X LLC, and the AVP X Committee Members each disclaim beneficial ownership except to any pecuniary interest therein.

SEC source: 0000899243-21-029077 · doc4.xml · nonDerivative · entry 1

ARCH Venture Partners X, LLC · CIK 0001769012 · 10% owner

ARCH Venture Fund X, L.P. · CIK 0001757011 · 10% owner

ARCH Venture Fund X Overage, L.P. · CIK 0001757017 · 10% owner

ARCH Venture Partners X, L.P. · CIK 0001782583 · 10% owner

ARCH Venture Partners X Overage, L.P. · CIK 0001768905 · 10% owner

NELSEN ROBERT · CIK 0001219042 · 10% owner

CRANDELL KEITH · CIK 0001219039 · 10% owner

Burow Kristina · CIK 0001569248 · 10% owner

GILLIS STEVEN · CIK 0001229592 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Indirect · By ARCH Venture Fund X, L.P.

Disclosed balance after: 5,527,777

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · price: The shares of the Issuer's Series A and Series B Preferred Stock automatically converted into shares of the Issuer's Common Stock, for no additional consideration, at a ratio of 1.2-for-1 share, immediately prior to the consummation of the Issuer's initial public offering.

F2 · ownership.nature: ARCH Venture Partners X, L.P. (AVP X LP) is the sole general partner of ARCH Venture Fund X, L.P. (ARCH X). ARCH Venture Partners X Overage, L.P. (AVP X Overage LP) is the sole general partner of ARCH Venture Fund X Overage, L.P. (ARCH X Overage). ARCH Venture Partners X, LLC (AVP X LLC) is the sole general partner of each of AVP X LP and AVP X Overage LP. Keith Crandell, Kristina Burow, Steven Gillis, and Robert Nelsen comprise the investment committee of AVP X LLC (the AVP X Committee Members). AVP X LP and AVP X Overage LP may be deemed to beneficially own the shares held by ARCH X and ARCH X Overage, respectively, AVP X LLC may be deemed to beneficially own the shares held by ARCH X and ARCH X Overage, and each of the AVP X Committee Members may be deemed to share the power to direct the disposition and vote of the shares held by ARCH X and ARCH X Overage.

F3 · ownership.nature: (Continued from Footnote 2) AVP X LP, AVP X Overage LP, AVP X LLC, and the AVP X Committee Members each disclaim beneficial ownership except to any pecuniary interest therein.

SEC source: 0001062993-21-006294 · form4.xml · nonDerivative · entry 3

Burow Kristina · CIK 0001569248 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 12,067

F1 · kind: Distribution of Common Stock held by a limited partnership to its partners for no consideration.

F4 · kind: Change from indirect to direct ownership of shares previously reported as beneficially owned by the Reporting Person.

SEC source: 0001062993-21-006294 · form4.xml · nonDerivative · entry 2

Burow Kristina · CIK 0001569248 · Director

10b5-1 filing: Not disclosed

Ownership: Indirect · See footnote

Disclosed balance after: 2,921,519

F1 · kind: Distribution of Common Stock held by a limited partnership to its partners for no consideration.

F3 · ownership.nature: The shares are directly held by ARCH Venture Fund IX Overage, L.P. ("ARCH Overage"). ARCH Venture Partners IX Overage, L.P. ("Overage GPLP"), as the sole general partner of ARCH Overage, may be deemed to beneficially own the shares held by ARCH Overage. GPLLC, as the sole general partner of Overage GPLP, may be deemed to beneficially own the shares held by Overage GPLP. The Reporting Person has an interest in the Overage GPLP and the GPLLC but does not have voting or investment control over the shares held by ARCH Overage. The Reporting Person disclaims ownership of such shares, except to the extent of her pecuniary interest therein.