Exhibit A AGREEMENT REGARDING THE JOINT FILING OF SCHEDULE 13DPolaris Venture Partners Iv Lp • May 26th, 2015 • Biological products, (no disgnostic substances)
The undersigned, being duly authorized thereunto, hereby execute this agreement as an exhibit to this Schedule 13D to evidence the agreement of the below-named parties, in accordance with the rules promulgated pursuant to the Securities Exchange Act of 1934, to file this Schedule jointly on behalf of each such party.
