Dubois-Stringfellow Nathalie bought SGMO

Footnotes

Represents shares of common stock issuable upon settlement of a restricted stock unit ("RSU") grant that will vest as to one-half (1/2) of the shares on the first anniversary of the grant date, and the remainder of the shares will vest in 4 successive equal quarterly installments thereafter, subject to the Reporting Person's Continuous Service (as defined in the Issuer's Amended and Restated 2018 Equity Incentive Plan, as amended (the "2018 EIP")) through each such date and subject to acceleration in full in the event of a Change in Control (as defined in the 2018 EIP).; Includes: (a) 8,001 shares subject to the Reporting Person's February 25, 2021 RSU grant that will vest in one final installment on February 25, 2024, (b) 21,141 shares subject to the Reporting Person's February 25, 2022 RSU grant that will vest in successive equal quarterly installments through February 25, 2025, and (c) 53,438 shares subject to Reporting Person's February 24, 2023 RSU grant that will vest as to one-quarter (1/4) of the shares on the first anniversary of the grant date, and the remainder of the shares will vest in 8 successive equal quarterly installments thereafter. The vesting of all such RSU grants is subject to the Reporting Person's Continuous Service (as defined in the 2018 EIP) through each such date and subject to acceleration as provided in the 2018 EIP.; Includes 5,000 shares acquired on November 30, 2023 under the Issuer's 2020 Employee Stock Purchase Plan.