X0206 3 2021-07-22 0 0001619856 Caribou Biosciences, Inc. CRBU 0001871155 Fischesser Ryan C/O CARIBOU BIOSCIENCES, INC. 2929 7TH STREET, SUITE 105 BERKELEY CA 94710 0 1 0 0 See Remarks Common Stock 98813 D Stock Option (Right to Buy) 2.68 2029-03-18 Common Stock 10266 D Stock Option (Right to Buy) 4.11 2031-03-29 Common Stock 27270 D The shares subject to this option have vested or will vest in equal monthly installments until the option is fully vested on January 1, 2023, subject to the reporting person's continued service to the Issuer thorough the applicable vesting date. 1/4th of the shares subject to this option will vest on January 1, 2022 and an additional 1/48th of the aggregate number of shares subject to the option will vest on the corresponding day of each month thereafter, subject to the reporting person's continued service to the Issuer thorough the applicable vesting date. Controller Exhibit 24 - Power of Attorney. /s/ Ryan Fischesser 2021-07-22