X0306 4 2022-07-05 0 0001783328 TScan Therapeutics, Inc. TCRX 0001936730 Barton Debora C/O TSCAN THERAPEUTICS, INC. 830 WINTER STREET WALTHAM MA 02451 0 1 0 0 Chief Medical Officer Stock Option (right to buy) 3.17 2022-07-05 4 A 0 150000 0.00 A 2032-07-04 Voting Common Stock 150000 150000 D The shares subject to this option will vest with respect to 25% of the shares after 12 months of continuous service to the Issuer following July 5, 2022, and the balance will vest in equal monthly installments over the next 36 months of continuous service to the Issuer. /s/ Debora Barton 2022-07-07