X0306 4 2018-04-03 0 0001622229 Unum Therapeutics Inc. UMRX 0001671219 Atlas Venture Fund IX, L.P. 25 FIRST STREET, SUITE 303 CAMBRIDGE MA 02141 0 0 1 0 0001671208 Atlas Venture Associates IX, L.P. 25 FIRST STREET, SUITE 303 CAMBRIDGE MA 02141 0 0 1 0 0001671207 Atlas Venture Associates IX, LLC 25 FIRST STREET, SUITE 303 CAMBRIDGE MA 02141 0 0 1 0 Common Stock 2018-04-03 4 C 0 3184446 A 3184446 D Common Stock 2018-04-03 4 C 0 83037 A 3267483 D Common Stock 2018-04-03 4 P 0 94052 12.00 A 3361535 D Series A Preferred Stock 2018-04-03 4 C 0 3184446 0.00 D Common Stock 3184446 0 D Series B Preferred Stock 2018-04-03 4 C 0 83037 0.00 D Common Stock 83037 0 D Each share automatically converted into Common Stock, for no additional consideration, on a 1.5701314513884-for-1 basis at the closing of the Issuer's initial public offering. The shares had no expiration date. The shares are held directly by Atlas Venture Fund IX, L.P. ("Atlas Venture Fund IX"). The general partner of Atlas Venture Fund IX is Atlas Venture Associates IX, L.P. ("AVA IX LP"). Atlas Venture Associates IX, LLC ("AVA IX LLC") is the general partner of AVA IX LP. Each of AVA IX LP and AVA IX LLC disclaim Section 16 beneficial ownership of the securities held by Atlas Venture Fund IX, except to the extent of its pecuniary interest therein, if any. Atlas Venture Fund IX, LP, By: Atlas Venture Associates IX, LP, its general partner, By: Atlas Venture Associates IX, LLC, its general partner, By: Frank Castellucci, General Counsel /s/ Frank Castellucci 2018-04-03 Atlas Venture Associates IX, LP, By: Atlas Venture Associates IX, LLC, its general partner, By: Frank Castellucci, General Counsel /s/ Frank Castellucci 2018-04-03 Atlas Venture Associates IX, LLC, By: Frank Castellucci, General Counsel /s/ Frank Castellucci 2018-04-03