The Wichita Falls, Texas native received his medical degree from Baylor College of Medicine in Houston, where he also completed his residency. He finished an oncology fellowship at The University of Texas MD Anderson Cancer Center, received an MBA at the University of Houston and is a fellow of the American College of Surgeons. Before assuming the presidency of UTMB Health, Callender served as UCLA Health’s associate vice chancellor and CEO from 2004 to 2007. He previously served in several leadership roles during more than 20 years with MD Anderson. He culminated his tenure there as executive vice president and chief operating officer.