X0206 3 2021-06-16 0 0001806952 Lyell Immunopharma, Inc. LYEL 0001723174 ARCH Venture Partners IX, LLC 8755 W. HIGGINS ROAD , SUITE 1025 CHICAGO IL 60631 0 0 1 0 0001666306 ARCH Venture Fund IX, L.P. 8755 W. HIGGINS ROAD SUITE 1025 CHICAGO IL 60631 0 0 1 0 0001666307 ARCH Venture Fund IX Overage, L.P. 8755 W. HIGGINS ROAD SUITE 1025 CHICAGO IL 60631 0 0 1 0 0001723172 ARCH Venture Partners IX Overage, L.P. 8755 W. HIGGINS ROAD SUITE 1025 CHICAGO IL 60631 0 0 1 0 0001723173 ARCH Venture Partners IX, L.P. 8755 W. HIGGINS ROAD SUITE 1025 CHICAGO IL 60631 0 0 1 0 0001219039 CRANDELL KEITH 8755 W. HIGGINS ROAD SUITE 1025 IL 60631 0 0 1 0 0001219043 BYBEE CLINTON 8755 W. HIGGINS ROAD SUITE 1025 CHICAGO IL 60631 0 0 1 0 Series A Convertible Preferred Stock 1.8288 Common Stock 17771216 I ARCH Venture Fund IX, L.P. Series A Convertible Preferred Stock 1.8288 Common Stock 17771216 I ARCH Venture Fund IX Overage, L.P. Series C Convertible Preferred Stock 11.4905 Common Stock 435142 I ARCH Venture Fund IX, L.P. Series C Convertible Preferred Stock 11.4905 Common Stock 435142 I ARCH Venture Fund IX Overage, L.P. The Series A Convertible Preferred Stock is convertible at any time, at the election of holder, has no expiration date, and will automatically convert to shares of the Issuer's Common Stock immediately prior to the closing of the Issuer's initial public offering on a 1-for-1 basis. ARCH Venture Partners IX, L.P. (AVP IX LP) is the sole general partner of ARCH Venture Fund IX, L.P. (ARCH IX). ARCH Venture Partners IX Overage, L.P. (AVP IX Overage LP) is the sole general partner of ARCH Venture Fund IX Overage, L.P. (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 the extent of any pecuniary interest therein. The Series C Convertible Preferred Stock is convertible at any time, at the election of holder, has no expiration date, and will automatically convert to shares of the Issuer's Common Stock immediately prior to the closing of the Issuer's initial public offering on a 1-for-1 basis. /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 2021-06-16 /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 2021-06-16 /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 2021-06-16 /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 2021-06-16 /s/ ARCH Venture Partners IX, LLC, its General Partner, By: Mark McDonnell, attorney in-fact 2021-06-16 /s/ Keith Crandell, By: Mark McDonnell, attorney in-fact 2021-06-16 /s/ Clinton Bybee, By: Mark McDonnell, attorney in-fact 2021-06-16