Dr. Mark M. Davis is the Director of the Stanford Institute for Immunology, Transplantation and Infection (ITI), a Professor of Microbiology and Immunology, and a Howard Hughes Medical Institute Investigator. He received a B.A. from Johns Hopkins University and a Ph.D. from the California Institute of Technology. He later was a postdoctoral fellow and staff fellow at the Laboratory of Immunology at NIH and later became a faculty member in the Department of Microbiology and Immunology at Stanford University School of Medicine, where he remains today.  Dr. Davis is well known for identifying many of the T-cell receptor genes, which are responsible for the ability of these cells to recognize a diverse repertoire of antigens. Other work in his laboratory pioneered studies of the biochemistry, genetics and cell biology of these molecules and T lymphocytes generally, which play a key role in orchestrating immune responses. His current research focuses on obtaining a “systems level” understanding of the human immune system. This has involved the steady state and vaccine responses of old and young subjects, as well as a recent study of twins, which concluded the variation in most immune system parameters is not driven by inherited variation, but rather by environmental factors.