This Note shall, at the election of the Company, be subject to payment in common stock of the Company, par value $0.0001 per share (the “ Common Stock ”), as provided and subject to the requirements of Sections 3.6.3 through 3.6.12 of that certain Sponsored Research Agreement, dated [____________, 2018], by and between the Company and the Broad Institute, Inc. (the “ Agreement ”).  Notwithstanding the foregoing, the Company shall have no obligation to make such election to issue Note Shares (as defined in the Agreement) as payment for this Note.