13.Controlled Equity Offering

In August 2015, we entered into a Controlled Equity OfferingSM Sales Agreement with Cantor Fitzgerald & Co. (“Cantor”), as sales agent, pursuant to which we may sell, through Cantor, up to an aggregate of $30.0 million in shares of our common stock. All sales of our common stock will be made pursuant to a shelf registration statement that was declared effective by the Securities and Exchange Commission (SEC) on July 13, 2015.  Cantor is acting as our sole sales agent for any sales made under the Sales Agreement for a low single-digit commission on gross proceeds.  The common stock is being sold at prevailing market prices at the time of the sale, and, as a result, prices may vary.  Unless otherwise terminated earlier, the Controlled Equity OfferingSM Sales Agreement continues until all shares available under the agreement have been sold.  As of September 30, 2015, we have not made any sales under the Sales Agreement.