X0306 4 2020-12-02 0 0001628171 Revolution Medicines, Inc. RVMD 0001569705 Third Rock Ventures III, L.P. C/O THIRD ROCK VENTURES, LLC NEWBURY STREET, 3RD FLOOR BOSTON MA 02116 0 0 1 0 0001637300 Third Rock Ventures GP III, L.P. 29 NEWBURY STREET, 3RD FLOOR BOSTON MA 02116 0 0 1 0 0001637299 TRV GP III, LLC 29 NEWBURY STREET, 3RD FLOOR BOSTON MA 02116 0 0 1 0 0001192603 STARR KEVIN P 29 NEWBURY STREET, 3RD FLOOR BOSTON MA 02116 0 0 1 0 0001192595 TEPPER ROBERT I 29 NEWBURY STREET, 3RD FLOOR BOSTON MA 02116 0 0 1 0 0001180428 LEVIN MARK J 29 NEWBURY STREET, 3RD FLOOR BOSTON MA 02116 0 0 1 0 Common Stock 2020-12-02 4 J 0 1000000 D 7024031 D Common Stock 1909317 I See footnote Common Stock 0 I See footnote Common Stock 14149 D Common Stock 1572 I See footnote Common Stock 15720 D Common Stock 15720 D On December 2, 2020, Third Rock Ventures III, L.P. ("TRV III") distributed for no consideration, 1,000,000 shares of Common Stock of the Issuer (the "Shares") to its limited partners and to Third Rock Ventures GP III, L.P. ("TRV GP III"), the general partner of TRV III, representing each such partner's pro rata interest in such Shares. On the same date, TRV GP III distributed, for no consideration, the Shares it received in the distribution by TRV III to its partners, representing each such partner's pro rata interest in such Shares. All of the aforementioned distributions were made in accordance with the exemptions afforded by Rules 16a-13 and 16a-9 of the Securities Exchange Act of 1934, as amended. These shares are directly held by TRV III. The general partner of TRV III is TRV GP III. The general partner of TRV GP III is TRV GP III, LLC ("TRV GP III LLC"). The individual managers of TRV GP III LLC are Mark Levin ("Levin"), Kevin Starr ("Starr") and Dr. Robert Tepper ("Tepper"). Each of TRV GP III, TRV GP III LLC, Levin, Starr and Tepper disclaims beneficial ownership of the shares except to the extent of its or his 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. These shares are directly held by Third Rock Ventures II, L.P. ("TRV II"). The general partner of TRV II is Third Rock Ventures GP II, L.P. ("TRV GP II"). The general partner of TRV GP II is TRV GP II, LLC ("TRV GP II LLC"). The individual managers of TRV GP II LLC are Levin, Starr and Tepper. Each of TRV GP II, TRV GP II LLC, Levin, Starr and Tepper disclaims beneficial ownership of these shares except to the extent of its or his 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 of Levin, Starr and Tepper is a partner of Third Rock Ventures GP IV, L.P., which is the general partner of Third Rock Ventures IV, L.P. ("TRV IV"). TRV IV directly holds 1,419,900 shares of Common Stock of the Issuer. Each of Levin, Starr and Tepper disclaims beneficial ownership over the shares held by TRV IV, except to the extent of his pecuniary interest therein, if any, and this report shall not be deemed an admission that he is the beneficial owner of such shares. The shares are directly held by Levin. Includes Shares received in the distributions described in footnote (1) above. The shares are directly held by Levin Family 2014 Irrevocable Trust. Includes Shares received in the distributions described in footnote (1) above. The shares are directly held by Starr. Includes Shares received in the distributions described in footnote (1) above. The shares are directly held by Tepper. Includes Shares received in the distributions described in footnote (1) above. /s/ Kevin Gillis, Chief Operating Officer of TRV GP III, LLC, general partner of Third Rock Ventures GP III, L.P., general partner of Third Rock Ventures III, L.P. 2020-12-04 /s/ Kevin Gillis, Chief Operating Officer of TRV GP III, LLC, general partner of Third Rock Ventures GP III, L.P. 2020-12-04 /s/ Kevin Gillis, Chief Operating Officer of TRV GP III, LLC 2020-12-04 /s/ Kevin Gillis, by power of attorney for Kevin Starr 2020-12-04 /s/ Kevin Gillis, by power of attorney for Dr. Robert Tepper 2020-12-04 /s/ Kevin Gillis, by power of attorney for Mark Levin 2020-12-04