Adrian Hayday graduated in biochemistry from Cambridge in 1978; studied for a PhD in molecular virology at the Imperial Cancer Research Fund (now the London Research Institute of CRUK); and undertook post-doctoral training with Susumu Tonegawa at MIT. In 1985, he was appointed to the Faculty at Yale University, where he progressed to Professor of Molecular, Cell, and Developmental Biology and Immunobiology. In 1997, he was the first serving biologist to be awarded Yale College’s most prestigious prize for scholarship, the William DeVane Medal, awarded annually to one member of the Faculty. In 1998, he moved his laboratory to London to build the Peter Gorer Dept of Immunobiology, and then the Division of Immunology, Infection and Inflammatory Diseases, both at King’s College. His research is most associated with gamma delta T cells, a novel and unanticipated T lymphocyte subset to whose discovery he substantially contributed in 1984. His study of these cells has provided new insights into the immune surveillance of stressed tissues; into tumour immunology; and into the unanticipated roles played by T cells in innate immunity. In 2009, he also established a basic research team at LRI-CRUK which aims to uncover new knowledge in lymphoid stress surveillance, and to provide a fluent translation of such findings via the clinical research programmes at King’s. Those programmes include immune-monitoring of neonates, and of adults post vaccination and during cancer therapy. Professor Hayday was also senior author on a Phase1B immunotherapy trial in treatment-recalcitrant prostate cancer that showed excellent safety and promising trends of efficacy. In 2010, Professor Hayday became founding co-Lead of the Clinical Academic Grouping (CAG) in Genetics Rheumatology Immunology, Infection, and Dermatology (GRIID) in King’s Health Partners. Among other activities, Professor Hayday has served on King’s College Council; on the Board of King’s College Enterprises; the Programme Committee of the Federation of Clinical Immunology Societies; and the Scientific Advisory Board of MedImmune. He is co-founder of ImmunoQure AG, and is a Fellow of the Academy of Medical Sciences. He previously chaired the funding committee in Basic Immunology and Infection for the Wellcome Trust, the funding committee of the American Cancer Society. He was or currently is advisor to the Howard Hughes Medical Institute, to the National Institutes of Health Human Immunology Project Consortium, to Kyoto University School of Medicine, to Institut Pasteur, and to the Max Planck Institute.