SUBSTITUTE POWER OF ATTORNEY


I, Mark J. Casey, the undersigned, by a Power of Attorney dated
April 14, 2014 (the "POA"), was appointed to act as the true
and lawful attorney-in-fact for and on behalf of Eric Compton
in his capacity as the Chief Operating Officer (the "Executive
Officer") of Hologic, Inc. (the "Company") to do and perform any
and all acts for and on behalf of the Executive Officer which may
be necessary or desirable to complete and execute any Forms 3, 4,
or 5, complete and execute any amendment(s) thereto, and timely
file such form(s) with the United States Securities and Exchange
Commission and any stock exchange or similar authority.

As authorized in the POA, I hereby delegate all of the powers contained
therein to each of Robert W. McMahon, Anne M. Liddy and Alisha
Hankins, individually and signing singly, to act as the Executive
Officer?s true and lawful substitute attorney-in-fact.

Further, the undersigned hereby ratifies all acts, deeds and things,
which any substitute attorney-in-fact will lawfully do and execute in
pursuance of the powers granted herein.

This Substitute Power of Attorney shall remain in full force and effect
until revoked by the undersigned, the POA is revoked or the Executive
Officer is no longer required to file Forms 3, 4, and 5 with respect
to the Executive Officer's holdings of and transactions in securities
issued by the Company.

IN WITNESS WHEREOF, the undersigned has caused this Substitute Power
of Attorney to be executed as of this 15th day of December, 2014.




/s/Mark J. Casey
Mark J. Casey
Attorney-in-fact