Washington, D.C. 20549


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 Number: 3235-0104
Estimated average burden
hours per response: 0.5
1. Name and Address of Reporting Person*
Harrington-Smith Kristen

(Last) (First) (Middle)


(City) (State) (Zip)
2. Date of Event Requiring Statement (Month/Day/Year)
3. Issuer Name and Ticker or Trading Symbol
ImmunoGen, Inc. [ IMGN ]
4. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
Director 10% Owner
X Officer (give title below) Other (specify below)
SVP & Chief Commercial Officer
5. If Amendment, Date of Original Filed (Month/Day/Year)
6. Individual or Joint/Group Filing (Check Applicable Line)
X Form filed by One Reporting Person
Form filed by More than One Reporting Person
Table I - Non-Derivative Securities Beneficially Owned
1. Title of Security (Instr. 4) 2. Amount of Securities Beneficially Owned (Instr. 4) 3. Ownership Form: Direct (D) or Indirect (I) (Instr. 5) 4. Nature of Indirect Beneficial Ownership (Instr. 5)
Table II - Derivative Securities Beneficially Owned
(e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 4) 2. Date Exercisable and Expiration Date (Month/Day/Year) 3. Title and Amount of Securities Underlying Derivative Security (Instr. 4) 4. Conversion or Exercise Price of Derivative Security 5. Ownership Form: Direct (D) or Indirect (I) (Instr. 5) 6. Nature of Indirect Beneficial Ownership (Instr. 5)
Date Exercisable Expiration Date Title Amount or Number of Shares
Explanation of Responses:
Exhibit 24.1 - Power of Attorney. No securities are beneficially owned.
No securities are beneficially owned.
/s/ Renee Lentini, attorney in fact 11/17/2021
** Signature of Reporting Person Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 5 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.

KNOW ALL BY THESE PRESENT, that the undersigned hereby constitutes
and appoints each of Renee Lentini and Joseph J. Kenny
of ImmunoGen, Inc. (the "Company"), acting singly, with full power of
substitution, the undersigned's true and lawful attorney-in-fact to:

(1) Execute for and on behalf of the undersigned, in the
undersigned's capacity as an officer, director and/or 10%
shareholder of the Company, Forms 3, 4 and 5, and amendments thereto,
in accordance with Section 16(a) of the Securities Exchange Act of 1934
and the rules thereunder;

(2) Do and perform any and all acts for and on behalf of
the undersigned which may be necessary or desirable to
complete and
execute any such Form 3, 4 or 5, or amendments thereto, and timely file
such form with
the United States Securities and Exchange Commission and
any stock
exchange or similar authority; and

(3) Take any other action of any type whatsoever in connection
the foregoing which, in the opinion of such attorney-in-fact,
be of benefit to, in the best interest of, or legally required
the undersigned, it being understood that the documents executed
by such attorney-in-fact on behalf of the undersigned pursuant
to this Power of Attorney shall be in such form and shall
contain such terms and conditions as such attorney-in-fact
may approve in such attorney-in-fact's discretion.

The undersigned hereby grants to each such attorney-in-fact
power and authority to do and perform any and every act and
thing whatsoever requisite, necessary, or proper to be done
in the
exercise of the rights and powers herein granted, as fully
to all intents and purposes as the undersigned might or
could do if
personally present, with full power of substitution or
revocation, hereby ratifying and confirming all that such attorney-in-fact, or
such attorney-in-fact's substitute or substitutes, shall
do or cause to be done by virtue of this Power of Attorney
and the rights and powers herein granted.  The undersigned
acknowledges that the foregoing attorneys-in-fact, in serving
in such capacity at the request of the undersigned, are not
assuming, nor is the Company assuming, any of the
undersigned's responsibilities to comply with Section 16 of the Securities
Exchange Act of 1934.

The undersigned agrees that each such attorney-in-fact shall not be liable for
any error of judgment or for any act done or omitted to be done or for any
mistake of fact or law except for each such attorney-in-fact's own bad faith,
and the
undersigned agrees to indemnify and to hold each such attorney-in-fact harmless
against any loss, claim, damage, liability or cost incurred on each such
attorney-in-fact's part arising out of or in connection with acts undertaken or
omitted to be taken as an attorney-in-fact hereunder.

This Power of Attorney shall remain in full force and effect until
the undersigned is no longer required to file Forms 3, 4 and
5 with respect to the undersigned's holdings of and
transactions in
securities issued by the Company, unless earlier revoked
by the undersigned in a signed writing delivered to the
foregoing attorneys-in-fact.

IN WITNESS WHEREOF, the undersigned has caused this Power of
Attorney to be executed this 15th day of November 2021.

/s/ Kristen Harrington-Smith

Print Name: Kristen Harrington-Smith