Exhibit 17.1

Electronic mail message:

From: William P. Barr

Sent: Tuesday, January 23, 2018 6:27PM

To:Daniel Och, Barry Griswell, Georganne Proctor, Jerome Kenney, Allan Bufferd, Katrina Paglia

Cc:David Levine

Subject:Resignation

Dan, Fellow Directors, and Katrina

This is to advise you that I am resigning from the board of directors, effective at the end of this month (January). If that timing causes any difficulties for the company, please let me know.

Bill Barr