Mr. Calhoun has a background in auditing and accounting, and has served as a Director and as Chair of the Company’s audit committee since February of 2016. Mr. Calhoun joined Ernst & Young LLP, a public accounting firm, in 1965 and served as a partner of the firm from 1975 until his retirement in 2002. Mr. Calhoun currently serves as a member of the Board of Directors, as a member of the Compensation Committee, and as Chair of the Audit Committee of NantHealth, Inc. and Ryerson Holding Corporation and previously served Great Basin Scientific, Inc, in the same capacities through 2017. Mr. Calhoun previously served on the boards and audit committees of 6 other public companies in the life sciences industry, including Abraxis Bioscience, Inc., Myogen, Inc., and Adams Respiratory Therapeutics, Inc. Mr. Calhoun also currently serves on the boards of 3 private companies in the life sciences industry. Mr. Calhoun received a Bachelor of Science in Accounting from the University of Southern California.