TScan Therapeutics (TCRX) SC 13G TScan Therapeutics / GV 2017 ownership change

EXHIBIT A

Agreement of Joint Filing

The undersigned hereby agree that a single Schedule 13G (or any amendment thereto) relating to the Voting Common Stock of TScan Therapeutics, Inc. shall be filed on behalf of each of the undersigned and that this Agreement shall be filed as an exhibit to such Schedule 13G.

Date: February 11, 2022

GV 2017, L.P.
By: GV 2017 GP, L.P., its General Partner
By: GV 2017 GP, L.L.C., its General Partner
By: Alphabet Holdings LLC, its Sole Member
By:	/s/ Kathryn W. Hall
Name:	Kathryn W. Hall
Title:	Secretary
GV 2017 GP, L.P.
By: GV 2017 GP, L.L.C., its General Partner
By: Alphabet Holdings LLC, its Sole Member
By:	/s/ Kathryn W. Hall
Name:	Kathryn W. Hall
Title:	Secretary
GV 2017 GP, L.L.C
By: Alphabet Holdings LLC, its Sole Member
By:	/s/ Kathryn W. Hall
Name:	Kathryn W. Hall
Title:	Secretary
GV 2019, L.P.
By: GV 2019 GP, L.P., its General Partner
By: GV 2019 GP, L.L.C., its General Partner
By: Alphabet Holdings LLC, its Sole Member
By:	/s/ Kathryn W. Hall
Name:	Kathryn W. Hall
Title:	Secretary
GV 2019 GP, L.P.
By: GV 2019 GP, L.L.C., its General Partner
By: Alphabet Holdings LLC, its Sole Member
By:	/s/ Kathryn W. Hall
Name:	Kathryn W. Hall
Title:	Secretary
GV 2019 GP, L.L.C.
By: Alphabet Holdings LLC, its Sole Member
By:	/s/ Kathryn W. Hall
Name:	Kathryn W. Hall
Title:	Secretary
Alphabet Holdings LLC
By:	/s/ Kathryn W. Hall
Name:	Kathryn W. Hall
Title:	Secretary
XXVI Holdings Inc.
By:	/s/ Kathryn W. Hall
Name:	Kathryn W. Hall
Title:	Assistant Secretary

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Alphabet Inc.
By:	/s/ Kathryn W. Hall
Name:	Kathryn W. Hall
Title:	Assistant Secretary

Page 18 of 18