Transaction Details

Footnotes

Represents shares held directly by ARCH Venture Fund X, L.P. ("ARCH X"). ARCH Venture Partners X, L.P. ("AVP X LP") is the sole general partner of ARCH X. | Represents shares held directly by ARCH Venture Fund X Overage, L.P. ("ARCH X Overage"). ARCH Venture Partners X Overage, L.P. ("AVP X Overage LP") is the sole general partner of ARCH X Overage. | ARCH Venture Partners X, LLC ("AVP X LLC") is the sole general partner of each of AVP X LP and AVP X Overage LP. In addition to the Reporting Person, Keith Crandell, Kristina Burow and Steve Gillis are also members of the investment committee of AVP X LLC (the "AVP X Investment Committee Members"). AVP X LP and AVP X Overage LP may be deemed to beneficially own the shares held by ARCH X and ARCH X Overage, respectively, AVP X LLC may be deemed to beneficially own the shares held by ARCH X and ARCH X Overage, and each of the AVP X Investment Committee Members may be deemed to share the power to direct the disposition and vote of the shares held by ARCH X and ARCH X Overage. AVP X LP, AVP X Overage LP, AVP X LLC, and the other AVP X Investment Committee Members have filed a separate Form 4 and disclaim beneficial ownership except to the extent of any pecuniary interest therein. | The Reporting Person is also an AVP X Investment Committee Member and may be deemed to share the power to direct the disposition and vote of own the shares held by ARCH X and ARCH X Overage. The Reporting Person disclaims beneficial ownership of such shares except to the extent of any pecuniary interest therein, and this report shall not be deemed an admission that such shares are beneficially owned by him for Section 16 or any other purpose. | Represents shares held directly by ARCH Venture Fund XII, L.P. ("ARCH XII"). ARCH Venture Partners XII, L.P. ("AVP XII LP") is the general partner of ARCH XII. ARCH Venture Partners XII, LLC (AVP XII LLC) is the general partner of AVP XII LP. In addition to the Reporting Person, Keith Crandell, Kristina Burow and Steven Gillis are also members of the investment committee of AVP XII LLC (the "AVP XII LLC Investment Committee Members"). Each of AVP XII LP and AVP XII LLC may be deemed to beneficially own the shares held by ARCH XII, and each of the AVP XII LLC Investment Committee Members may be deemed to share the power to direct the disposition and vote of the shares held by ARCH XII. Each of AVP XII LP, AVP XII LLC and the other AVP XII LLC Investment Committee Members have filed a separate Form 4 and disclaim beneficial ownership except to the extent of their pecuniary interest therein, if any. | The Reporting Person is also an AVP XII Investment Committee Member and may be deemed to to share the power to direct the disposition and vote of the shares held by ARCH XII. The Reporting Person disclaims beneficial ownership of such shares except to the extent of any pecuniary interest therein, and this report shall not be deemed an admission that such shares are beneficially owned by him for Section 16 or any other purpose. | Shares held by a trust for the benefit of family members of the Reporting Person.