LIMITED POWER OF ATTORNEY

The undersigned hereby constitutes and appoints each of Teresa Jurgensen and
Chip Baird, and each of them individually, and with full power of substitution,
the undersigned's true and lawful attorney-in-fact to:

       (1) 	Complete and execute for and on behalf of the undersigned, in the
undersigned's capacity as an officer, director and/or ten percent (10%)
shareholder of 2seventy bio, Inc., a Delaware corporation (the "Company") any
and all instruments, certificates and documents required to be executed on
behalf of the undersigned as an individual or on behalf of the undersigned's
company or partnership, as the case may be, pursuant to Section 13 and Section
 16 of the Securities Exchange Act of 1934, as amended (the "Exchange Act") or
the rules and regulations 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
 instruments, certificates or documents required to be filed pursuant to
Sections 13 and 16 of the Exchange Act or the rules or regulations thereunder
and timely file such forms with the United States Securities and Exchange
Commission (the "SEC") and any stock exchange or similar authority;

       (3) 	Execute for and on behalf of the undersigned, from time to time
a Form ID, including any attached documents (such as Update Passphrase
Authentication), to effect the assignment of codes to the undersigned to be used
 in the transmission of information to the SEC using the EDGAR System; and

       (4) 	Take any other action of any type whatsoever in connection with
the foregoing which, in the opinion of such attorney-in-fact, may be of benefit
 to, in the best interest of, or legally required by, the undersigned, it being
 understood that the documents executed by any 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, acting
singly, full power and authority to do and perform any and every act which is
necessary, proper or desirable to be done in the exercise of any 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 any such
 attorney-in-fact, or any such attorney-in-fact's substitute or substitutes,
shall lawfully do or cause to be done by virtue of this Power of Attorney
and the rights and powers herein granted.

           The undersigned acknowledges that each of 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 13 or Section 16 of the
 Exchange Act or the rules or regulations thereunder.  The undersigned hereby
 agrees to indemnify each attorney-in-fact and the Company from and against
 any demand, damage, loss, cost or expense arising from any false or
misleading information provided by the undersigned to such attorney-in fact.

       This Power of Attorney shall remain in full force and effect until the
undersigned is no longer required to file any instruments, certificates and
documents pursuant to Section 13 and 16 of the Exchange Act or the rules or
regulations thereunder 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 as of December 21, 2022.



							Signature:	 /s/ Wei Lin
								    	 Wei Lin, MD









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