POWER OF ATTORNEY

     KNOW ALL BY THESE PRESENTS, that the undersigned hereby authorizes Jeffrey
S. Hackman, Michael G. Campbell, Jeffrey L. Quillen, Ryan M. Rourke Reed and
Stacie S. Aarestad, each acting singly, to execute and caused to be filed with
the United States Securities and Exchange Commission any and all documents or
filings, includingany amendments thereto, required to be so filed. The
undersigned hereby grantsto the attorney-in-fact full 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 any of the rights and powers herein
granted, as fully to all intents and purposes as the undersigned might or could
do personally present, with full power of substitution, resubstitution or
revocation, hereby ratifying and confirming all that such attorney-in-fact, or
such attorney's-in-fact 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 the foregoing attorney-in-fact, in
serving in such capacity at the request of the undersigned, is not assuming any
of the undersigned's responsibilities to comply with all applicable laws,
including Sections 13 and 16 of the Securities Exchange Act of 1934.

     This Power of Attorney shall remain in full force and effect until revoked
by the undersigned in a signed writing delivered to the foregoing attorney-in-
fact.

     IN WITNESS WHEREOF, the undersigned has caused this Power of Attorney to
be executed as of this 10th day of August, 2022.

/s/ Kirsten Flowers
Name: Kirsten Flowers