X0206 3 2020-02-12 0 0001628171 Revolution Medicines, Inc. RVMD 0001688327 Third Rock Ventures IV, L.P. C/O THIRD ROCK VENTURES, LLC, 29 NEWBURY STREET, 3RD FLOOR BOSTON MA 02116 0 0 1 0 0001688326 Third Rock Ventures GP IV, L.P. 29 NEWBURY STREET, 3RD FLOOR BOSTON MA 02116 0 0 1 0 0001688325 TRV GP IV, LLC 29 NEWBURY STREET, 3RD FLOOR BOSTON MA 02116 0 0 1 0 Series A Convertible Preferred Stock Common Stock 1027516 D Series B Convertible Preferred Stock Common Stock 342505 D Series C Convertible Preferred Stock Common Stock 49879 D These shares are directly held by Third Rock Ventures IV, L.P. ("TRV IV"). The general partner of TRV IV is Third Rock Ventures GP IV, L.P. ("TRV GP IV"). The general partner of TRV GP IV is TRV GP IV, LLC ("TRV GP IV LLC"). Each of TRV GP IV and TRV GP IV LLC disclaims beneficial ownership of these shares except to the extent of its pecuniary interest therein, if any, and this report shall not be deemed an admission that it or he is the beneficial owner of such shares. Each share of Series A Preferred Stock, Series B Convertible Stock and Series C Preferred Stock is convertible, at any time, at the holder's election, into Common Stock of the Issuer on a 1 for 1 basis. In addition, effective upon the closing of the Issuer's initial public offering of its Common Stock, each share of preferred stock will automatically convert on a 1 for 1 basis without payment of consideration. The preferred stock has no expiration date. /s/ Kevin Gillis, Chief Operating Officer of TRV GP IV, LLC, general partner of Third Rock Ventures GP IV, L.P., general partner of Third Rock Ventures IV, L.P. 2020-02-12 /s/ Kevin Gillis, Chief Operating Officer of TRV GP IV, LLC, general partner of Third Rock Ventures GP IV, L.P. 2020-02-12 /s/ Kevin Gillis, Chief Operating Officer of TRV GP IV, LLC 2020-02-12