Our Board of Directors (the “Board”) has made these materials available to you on the Internet, or has delivered printed versions of these materials to you by mail, in connection with the solicitation of proxies to be voted at our Annual Meeting of Stockholders to be held on April 19, 2018, at 3:00 p.m., Pacific Daylight Time, at the location and for the purposes as set forth in the “Notice of Annual Meeting of Stockholders.” Our stockholders are invited to attend the Annual Meeting and are requested to vote on the proposals described in this Proxy Statement. The approximate date on which this Proxy Statement and form of proxy will be first sent and made available to stockholders is March 9, 2018.