| Name | Ownership | Shares Owned | sole voting power | shared voting power | Signature | Title | CIK |
|---|---|---|---|---|---|---|---|
| Third Rock Ventures IV, L.P. | 6.97% | 9.37M | 0 | 9.37M | /s/ Kevin Gillis | Kevin Gillis, COO of TRV GP IV, LLC, the general partner of Third Rock Ventures GP IV, L.P., the general partner of Third Rock Ventures IV, L.P. | 0001688327 |
| Third Rock Ventures GP IV, L.P. | 6.97% | 9.37M | 0 | 9.37M | /s/ Kevin Gillis | Kevin Gillis, COO of TRV GP IV, LLC, the general partner of Third Rock Ventures GP IV, L.P. | 0001688326 |
| TRV GP IV, LLC | 6.97% | 9.37M | 0 | 9.37M | /s/ Kevin Gillis | Kevin Gillis, COO | 0001688325 |