Security	Date	Code	Shares	Price	A/D	Owned after	D/I	Nature of ownership
Common Stock^F1,F2	May 23, 2016	S	435	$0.01	D	8,965	I	By Versant Side Fund III, L.P.
Common Stock^F1,F2	May 23, 2016	S	1,080	$0.01	D	7,885	I	By Versant Side Fund III, L.P.
Common Stock^F1,F2	May 23, 2016	P	3,523	$5.00	A	11,408	I	By Versant Side Fund III, L.P.
Common Stock^F1,F2	May 23, 2016	S	73,615	$0.01	D	1,517,531	I	By Versant Venture Capital III, L.P.
Common Stock^F1,F2	May 23, 2016	S	182,914	$0.01	D	1,334,617	I	By Versant Venture Capital III, L.P.
Common Stock^F1,F2	May 23, 2016	P	596,477	$5.00	A	1,931,094	I	By Versant Venture Capital III, L.P.

Table II — derivative securities

No Table II lines on this filing.

Explanation of responses

F1Common stock held of record, respectively, by each of Versant Side Fund III, L.P. and Versant Venture Capital III, L.P., (the "Versant Venture Funds"). Versant Ventures III, LLC is the general partner of the Versant Venture Funds and has voting and dispositive control over securities held by the Versant Venture Funds. Brian G. Atwood, Samuel D. Colella, Ross Jaffe, M.D., William J. Link, Barbara N. Lubash, Donald B. Milder, Bradley J. Bolzon, Charles M. Warden, Robin L. Praeger and Rebecca R. Robertson are the managing directors of Versant Ventures III, LLC and are deemed to have voting and dispositive power over the shares and may be deemed to beneficially own shares held by the Versant Venture Funds. Brian G. Atwood is a managing member of and owns an interest in Versant Ventures III, LLC.
F2Accordingly, Brian G. Atwood may be deemed to beneficially own the securities held by the Versant Venture Funds. Each of Brian G. Atwood, Samuel D. Colella, Ross Jaffe, M.D., William J. Link, Barbara N. Lubash, Donald B. Milder, Bradley J. Bolzon, Charles M. Warden, Robin L. Praeger and Rebecca R. Robertson disclaims beneficial ownership of these securities except to the extent of their pecuniary interest therein.

Remarks

This Form 4 is the first of two filings by Brian G. Atwood. Rebecca R. Robertson, Charles M. Warden and Bradley J. Bolzon (the "Other Filers") are also reporting persons. Since the SEC's filing system will not accept CIK and CCC codes from more than ten joint filers of a report, the Other Filers have filed a separate Form 4 that relates to the same securities reported herein. Thus, in total, there are 13 joint filers: the Other Filers and each person that is a signatory to this Form 4.