X0306 4 2017-02-22 0 0001590750 MIRAGEN THERAPEUTICS, INC. MGEN 0001191818 LEFKOFF KYLE C/O MIRAGEN THERAPEUTICS, INC. 6200 LOOKOUT ROAD BOULDER CO 80301 1 0 0 0 Common Stock 2017-02-22 4 S 0 4102 14.3554 D 496331 I See Footnote Common Stock 2017-02-23 4 S 0 1800 13.6477 D 494531 I See Footnote Common Stock 1607437 I See Footnote The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $14.28 to $14.65, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each price within the ranges set forth in this footnote. All of the shares are held by Boulder Ventures VI, L.P. ("BV VI LP"). BV Partners VI, LLC ("BV VI LLC"), the general partner of BV VI LP may be deemed to indirectly beneficially own the shares. Kyle A. Lefkoff, Peter A. Roshko and Jonathan L. Perl are managing members of BV VI LLC, and each share voting and dispositive power over the shares held by BV VI LP. The Reporting Person disclaims beneficial ownership of the shares, except to the extent of his pecuniary interest therein, if any. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $13.50 to $14.00, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each price within the ranges set forth in this footnote. All of the shares are held by Boulder Ventures V, L.P. ("BV V LP"). BV Partners V, LLC ("BV V LLC"), the general partner of BV V LP may be deemed to indirectly beneficially own the shares. Kyle A. Lefkoff, Peter A. Roshko and Jonathan L. Perl are managing members of BV V LLC, and each share voting and dispositive power over the shares held by BV V LP. The Reporting Person disclaims beneficial ownership of the shares, except to the extent of his pecuniary interest therein, if any. /s/ Brent D. Fassett, as Attorney-in-Fact for Kyle A. Lefkoff 2017-02-24