X0206 3 2021-02-03 0 0001770121 Sana Biotechnology, Inc. SANA 0001757011 ARCH Venture Fund X, L.P. 8755 WEST HIGGINS ROAD SUITE 1025 CHICAGO IL 60631 0 0 1 0 0001666306 ARCH Venture Fund IX, L.P. 8755 WEST HIGGINS ROAD, SUITE 1025 CHICAGO IL 60631 0 0 1 0 0001666307 ARCH Venture Fund IX Overage, L.P. 8755 WEST HIGGINS ROAD, SUITE 1025 CHICAGO IL 60631 0 0 1 0 0001757017 ARCH Venture Fund X Overage, L.P. 8755 WEST HIGGINS ROAD, SUITE 1025 CHICAGO IL 60631 0 0 1 0 0001723172 ARCH Venture Partners IX Overage, L.P. 8755 WEST HIGGINS ROAD, SUITE 1025 CHICAGO IL 60631 0 0 1 0 0001782583 ARCH Venture Partners X, L.P. 8755 WEST HIGGINS ROAD, SUITE 1025 CHICAGO IL 60631 0 0 1 0 0001768905 ARCH Venture Partners X Overage, L.P. 8755 WEST HIGGINS ROAD, SUITE 1025 CHICAGO IL 60631 0 0 1 0 0001723174 ARCH Venture Partners IX, LLC 8755 WEST HIGGINS ROAD, SUITE 1025 CHICAGO IL 60631 0 0 1 0 0001769012 ARCH Venture Partners X, LLC 8755 WEST HIGGINS ROAD, SUITE 1025 CHICAGO IL 60631 0 0 1 0 Common Stock 147500 I See Footnotes Common Stock 145000 I See Footnotes Series A-1 Convertible Preferred Stock Common Stock 3687500 I See Footnotes Series A-1 Convertible Preferred Stock Common Stock 3687500 I See Footnotes Series A-2 Convertible Preferred Stock Common Stock 5687500 I See Footnotes Series A-2 Convertible Preferred Stock Common Stock 9375000 I See Footnotes Series A-2 Convertible Preferred Stock Common Stock 9375000 I See Footnotes Series A-2 Convertible Preferred Stock Common Stock 5687500 I See Footnotes Series B Convertible Preferred Stock Common Stock 781250 I See Footnotes Series B Convertible Preferred Stock Common Stock 781250 I See Footnotes Series B Convertible Preferred Stock Common Stock 2343750 I See Footnotes Series B Convertible Preferred Stock Common Stock 2343750 I See Footnotes Represents shares held directly by ARCH Venture Fund IX, L.P. (ARCH IX). ARCH Venture Partners IX, L.P. (AVP IX LP) is the sole general partner of ARCH IX. Represents shares held directly by ARCH Venture Fund IX Overage, L.P. (ARCH IX Overage). ARCH Venture Partners IX Overage, L.P. (AVP IX Overage LP) is the sole general partner of ARCH IX Overage. ARCH Venture Partners IX, LLC (AVP IX LLC) is the sole general partner of each of AVP IX LP and AVP IX Overage LP. Keith Crandell and Clinton Bybee are managing directors of AVP IX LLC (the AVP IX MDs). AVP IX LP and AVP IX Overage LP may be deemed to beneficially own the shares held by ARCH IX and ARCH IX Overage, respectively, AVP IX LLC may be deemed to beneficially own the shares held by ARCH IX and ARCH IX Overage, and each of the AVP IX MDs may be deemed to share the power to direct the disposition and vote of the shares held by ARCH IX and ARCH IX Overage. AVP IX LP, AVP IX Overage LP, AVP IX LLC, and the AVP IX MDs each disclaim beneficial ownership except to to the extent of any pecuniary interest therein. 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. 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. 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. The shares of Issuer's Preferred Stock automatically convert into shares of Issuer's Common Stock, for no additional consideration, on a 1-for-1 basis immediately prior to the consummation of Issuer's initial public offering. The expiration date is not relevant to the conversion of these securities. Exhibit 24 - Power of Attorney. Exhibit 24.1 - Power of Attorney Form 1 of 2. /s/ ARCH Venture Fund X, L.P., By: ARCH Venture Partners X, L.P., its General Partner, By: ARCH Venture Partners X, LLC, its General Partner, By: Mark McDonnell,: attorney in-fact 2021-02-03 /s/ ARCH Venture Fund X Overage, L.P., By: ARCH Venture Partners X Overage, L.P., its General Partner, By: ARCH Venture Partners X, LLC, its General Partner, By: Mark McDonnell, attorney in-fact 2021-02-03 /s/ ARCH Venture Fund IX, L.P., By: ARCH Venture Partners IX, L.P., its General Partner, By: ARCH Venture Partners IX, LLC, its General Partner, By: Mark McDonnell, attorney in-fact 2021-02-03 /s/ ARCH Venture Fund IX Overage, L.P., By: ARCH Venture Partners IX Overage, L.P., its General Partner, By: ARCH Venture Partners IX, LLC, its General Partner, By: Mark McDonnell, attorney in-fact 2021-02-03 /s/ ARCH Venture Partners X, L.P., its General Partner, By: ARCH Venture Partners X, LLC, its General Partner, By: Mark McDonnell, attorney in-fact 2021-02-03 /s/ ARCH Venture Partners X Overage, L.P., its General Partner, By: ARCH Venture Partners X, LLC, its General Partner, By: Mark McDonnell, attorney in-fact 2021-02-03 /s/ ARCH Venture Partners X, LLC, its General Partner, By: Mark McDonnell, attorney in-fact 2021-02-03 /s/ ARCH Venture Partners IX, L.P., its General Partner, By: ARCH Venture Partners IX, LLC, its General Partner, By: Mark McDonnell, attorney in-fact 2021-02-03 /s/ ARCH Venture Partners IX Overage, L.P., its General Partner, By: ARCH Venture Partners IX, LLC, its General Partner, By: Mark McDonnell, attorney in-fact 2021-02-03 /s/ ARCH Venture Partners IX, LLC, its General Partner, By: Mark McDonnell, attorney in-fact 2021-02-03