POWER OF ATTORNEY

The undersigned individual (the "Reporting Person") hereby constitutes
and appoints each of Patrick J. Christmas, Kenneth T. Mills and Vittal
K. Vasista, signing singly, with full power of substitution, as the
Reporting Person's true and lawful attorney in fact to:

(1) prepare and file on behalf of such Reporting Person any and all
reports, notices, communications and other documents (including, but
not limited to, reports on Schedule 13D, Schedule 13G, Form 13-F,
Form 3, Form 4 and Form 5) that such Reporting Person may be
required to file with the Securities and Exchange Commission (the
"SEC") pursuant to the Securities Act of 1933, as amended and the
Securities Exchange Act of 1934, as amended (together with the
implementing regulations thereto, the "Exchange Act") (collectively, the
"Reports") with respect to the Reporting Person's ownership of, or
transactions in, the securities of REGENXBIO Inc. (the "Company")
(whether directly or indirectly owned) by such Reporting Person;

(2) do and perform any and all acts for and on behalf of the Reporting
Person which may be necessary or desirable to complete and execute
any such Reports, complete and execute any amendment or amendments
thereto, and timely file such form with the SEC and any stock exchange
or similar authority; and

(3) 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 Reporting
Person, it being understood that the documents executed by such
attorney in fact on behalf of the Reporting Person 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 Reporting Person hereby grants to such 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 Reporting Person 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 lawfully do or cause to be done by virtue of this power
of attorney and the rights and powers herein granted. The Reporting
Person acknowledges that the foregoing attorney in fact, in serving in
such capacity at the request of the Reporting Person, is not assuming
any of the Reporting Person's responsibilities to comply with Section 16
of the Exchange Act.

This Power of Attorney with respect to the Reporting Person shall
remain in full force and effect until such Reporting Person is no longer
required to file any Reports with respect to the Reporting Person's
ownership of, or transactions in, the securities of the Company, unless
earlier revoked 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 15th day of April, 2019.

/s/ Steve Pakola
Steve Pakola