X0306 4 2021-03-16 1 0001718852 Prometheus Biosciences, Inc. RXDX 0001850122 Point72 Biotech Private Investments, LLC C/O POINT72, L.P. 72 CUMMINGS POINT ROAD STAMFORD CT 06902 0 0 0 1 Former 10% Owner 0001850121 Differentiated Ventures Investments, LLC C/O POINT72, L.P. 72 CUMMINGS POINT ROAD STAMFORD CT 06902 0 0 0 1 Former 10% Owner 0001832749 72 Investment Holdings, LLC C/O POINT72, L.P. 72 CUMMINGS POINT ROAD STAMFORD CT 06902 0 0 0 1 Former 10% Owner 0000905226 COHEN STEVEN A/SAC CAPITAL MGMT LP C/O POINT72, L.P. 72 CUMMINGS POINT ROAD STAMFORD CT 06902 0 0 0 1 Former 10% Owner Common Stock 2021-03-16 4 C 0 763327 A 763327 I See Footnote Common Stock 2021-03-16 4 C 0 1084697 A 1848024 I See Footnote Common Stock 2021-03-16 4 P 0 800000 19.00 A 2648024 I See Footnote Series D-1 Preferred Stock 2021-03-16 4 C 0 7633277 D Common Stock 763327 0 I See Footnote Series D-2 Preferred Stock 2021-03-16 4 C 0 10846968 D Common Stock 1084697 0 I See Footnote The shares of the Issuer's Series D-1 Preferred Stock automatically converted into shares of the Issuer's common Stock, for no additional consideration, at a ratio of ten-for-one share, immediately prior to the consummation of the Issuer's initial public offering. The securities reported herein may be deemed to be beneficially owned by each: (i) Differentiated Ventures Investments, LLC (DVI), which is deemed the beneficial owner of shares held by Point72 Biotech Private Investments, LLC (Point72 Biotech), (ii) 72 Investment Holdings, LLC (72 IH), the sole member of DVI, deemed to have sole voting and investment control over such interest held by DVI, and (iii) Steven A. Cohen (SC), the sole member of 72 IH, deemed to have sole voting and investment control over such interest held by 72 IH. Each of SC, 72 IH, and DVI disclaims beneficial ownership of such shares except to the extent of any pecuniary interest therein. The shares of the Issuer's Series D-2 Preferred Stock automatically converted into shares of the Issuer's common Stock, for no additional consideration, at a ratio of ten-for-one share, immediately prior to the consummation of the Issuer's initial public offering. Point72 Associates, LLC (the Fund) is the direct owner of 800,000 shares of Common Stock. SC may be deemed to have an indirect pecuniary interest in such shares of Common Stock as an indirect holder of interests in the Fund. Consist of shares of Series D-1 Preferred Stock held directly by Point72 Biotech. Consist of shares of Series D-2 Preferred Stock held directly by Point72 Biotech. Point72 Biotech Private Investments, LLC by: /s/ Vincent Tortorella, Authorized Signatory 2021-03-17 Differentiated Ventures Investments, LLC by: /s/ Vincent Tortorella, Authorized Signatory 2021-03-17 72 Investment Holdings, LLC by: /s/ Vincent Tortorella 2021-03-17 /s/ Steven A Cohen 2021-03-17