Peter Alan Bretscher is a Emeritus Professor of Microbiology and Immunology at the University of Saskatchewan. He received his B.A. and Ph.D. from the University of Cambridge in 1964 and 1968, respectively. He is interested in both theoretical and experimental aspects of the immunology and in basic and clinical problems. His basic studies have focused on how immune responses are regulated to achieve the attribute of self–non-self discrimination and to control the class of immunity generated. He has attempted to apply basic understanding to develop strategies to prevent and treat autoimmunity, cancer and infectious diseases.