X0206 3 2021-02-03 0 0001770121 Sana Biotechnology, Inc. SANA 0001219042 NELSEN ROBERT 8755 WEST HIGGINS ROAD, SUITE 1025 CHICAGO IL 60631 1 0 0 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 These shares are directly held 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. These shares are directly held 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. The Reporting Person is a managing director of AVP IX LLC ("AVP IX MD"). 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 the AVP IX MD 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 and AVP IX LLCeach disclaim beneficial ownership except to the extent of any pecuniary interest therein. These shares are directly held 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. These shares are directly held 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. The Reporting Person is on the investment committee of AVP X LLC ("AVP X Committee Member"). 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 the AVP X Committee Member 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, and AVP X LLC, each disclaim beneficial ownership except to to the extent of any pecuniary interest therein. The Reporting Person is an AVP IX MD and an AVP X Committee Member and may be deemed to beneficially own the shares held by ARCH IX, ARCH IX Overage, ARCH X, and ARCH X Overage. The Reporting Person disclaims beneficial ownership of such shares except to the extent of his pecuniary interest therein, if any. 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. /s/ James J. MacDonald, Attorney-in-Fact for Robert Nelsen 2021-02-03