SEC Form 4

FORM 4		UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934 or Section 30(h) of the Investment Company Act of 1940	OMB APPROVAL OMB Number: 3235-0287 Estimated average burden hours per response: 0.5
	Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

1. Name and Address of Reporting Person* BAKER BROS. ADVISORS LP (Last) (First) (Middle) 860 WASHINGTON STREET, 3RD FLOOR (Street) NEW YORK NY 10014 (City) (State) (Zip)	2. Issuer Name and Ticker or Trading Symbol TScan Therapeutics, Inc. [ TCRX ]	5. Relationship of Reporting Person(s) to Issuer (Check all applicable) X Director X 10% Owner Officer (give title below) Other (specify below)
	3. Date of Earliest Transaction (Month/Day/Year) 06/01/2022
	4. If Amendment, Date of Original Filed (Month/Day/Year)	6. Individual or Joint/Group Filing (Check Applicable Line) Form filed by One Reporting Person X Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	3. Transaction Code (Instr. 8)		4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5)			5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4)	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
			Code	V	Amount	(A) or (D)	Price

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	4. Transaction Code (Instr. 8)		5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)		6. Date Exercisable and Expiration Date (Month/Day/Year)		7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4)		8. Price of Derivative Security (Instr. 5)	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
				Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares
Non- Qualified Stock Option (right to buy)	$3.17	06/01/2022		A		9,146		(1)	05/31/2032	Common Stock	9,146	$0.00	9,146	I	See Footnotes(1)(2)(3)(4)

1. Name and Address of Reporting Person* BAKER BROS. ADVISORS LP (Last) (First) (Middle) 860 WASHINGTON STREET, 3RD FLOOR (Street) NEW YORK NY 10014 (City) (State) (Zip)

1. Name and Address of Reporting Person* 667, L.P. (Last) (First) (Middle) 860 WASHINGTON STREET, 3RD FLOOR (Street) NEW YORK NY 10014 (City) (State) (Zip)

1. Name and Address of Reporting Person* BAKER FELIX (Last) (First) (Middle) 860 WASHINGTON STREET, 3RD FLOOR (Street) NEW YORK NY 10014 (City) (State) (Zip)

1. Name and Address of Reporting Person* BAKER JULIAN (Last) (First) (Middle) 860 WASHINGTON STREET, 3RD FLOOR (Street) NEW YORK NY 10014 (City) (State) (Zip)

1. Name and Address of Reporting Person* Baker Bros. Advisors (GP) LLC (Last) (First) (Middle) 860 WASHINGTON STREET, 3RD FLOOR (Street) NEW YORK NY 10014 (City) (State) (Zip)

1. Name and Address of Reporting Person* Baker Brothers Life Sciences LP (Last) (First) (Middle) 860 WASHINGTON STREET, 3RD FLOOR (Street) NEW YORK NY 10014 (City) (State) (Zip)

Explanation of Responses:

1. 9,146 non-qualified stock options ("Stock Options") exercisable solely into common stock of TScan Therapeutics, Inc. (the "Issuer") were granted under the Issuer's 2021 Equity Incentive Plan to Dr. Stephen Biggar, a full-time employee of Baker Bros. Advisors LP (the "Adviser") in his capacity as a director of the Issuer. The Stock Options with a strike price of $3.17 vest in full upon the earlier of the first anniversary of the grant date or the Issuer's 2023 annual meeting, subject to Dr. Biggar's continued service on the board of directors of the Issuer (the "Board"). The Stock Options expire on May 31, 2032. Dr. Biggar serves on the Board as a representative of Baker Brothers Life Sciences, L.P. ("Life Sciences") and 667, L.P. ("667", and together with Life Sciences, the "Funds").

2. The policies of the Funds and the Adviser do not permit full-time employees of the Adviser or managing members of the Adviser GP (as defined below) to receive compensation for serving as a director of the Issuer. The Funds are entitled to receive all of the pecuniary interest in the securities issued. The Funds each own an indirect proportionate pecuniary interest in the Stock Options. Solely as a result of Felix J. Baker's and Julian C. Baker's ownership interest in (i) the general partners of the Funds and (ii) the Funds, Felix J. Baker and Julian C. Baker may be deemed to have an indirect pecuniary interest in the Stock Options (i.e. no direct pecuniary interest).

3. The Adviser serves as the investment adviser to the Funds. In connection with the services provided by the Adviser, the Adviser receives an asset-based management fee that does not confer any pecuniary interest in the securities held by the Funds. Baker Bros. Advisors (GP) LLC (the "Adviser GP") is the Adviser's sole general partner. Julian C. Baker and Felix J. Baker are managing members of the Adviser GP. The Adviser has complete and unlimited discretion and authority with respect to the investment and voting power of the securities held by the Funds. The general partners of the Funds have relinquished to the Adviser all discretion and authority with respect to the investment and voting power of the securities held by the Funds. The Adviser has investment and dispositive power over the Stock Options and any common stock of the Issuer received as a result of the exercise of Stock Options.

4. Julian C. Baker, Felix J. Baker, the Adviser GP and the Adviser disclaim beneficial ownership of the securities held directly by the Funds except to the extent of their pecuniary interest therein, and this report shall not be deemed an admission that any of Julian C. Baker, Felix J. Baker, the Adviser GP or the Adviser is a beneficial owner of such securities for purposes of Section 16 or any other purpose.

Remarks:

Dr. Stephen R. Biggar, a full-time employee of Baker Bros. Advisors LP, is a director of TScan Therapeutics, Inc. (the "Issuer"). By virtue of their representation on the board of directors of the Issuer, for purposes of Section 16 of the Securities Exchange Act of 1934, as amended, the reporting persons are deemed directors by deputization of the Issuer.

	By: Baker Bros. Advisors LP, Name: Scott L. Lessing, Title: President /s/ Scott L. Lessing	06/03/2022
	Adviser to 667, L.P., pursuant to authority granted by Baker Biotech Capital, L.P., GP to 667, L.P. Name: Scott L. Lessing, Title: President /s/ Scott L. Lessing	06/03/2022
	/s/ Felix J. Baker	06/03/2022
	/s/ Julian C. Baker	06/03/2022
	By: Baker Bros. Advisors (GP) LLC, Name: Scott L. Lessing, Title: President /s/ Scott L. Lessing	06/03/2022
	Baker Bros. Advisors LP, Mgmt. Co. and Inv. Adviser to BAKER BROTHERS LIFE SCIENCES, L.P., pursuant to authority granted by Baker Brothers Life Sciences Capital, L.P., GP to Baker Brothers Life Sciences, L.P., Name: Scott L. Lessing, Title: President /s/	06/03/2022
	** Signature of Reporting Person	Date
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