George Kassiotis is currently a Senior Group Leader and head of the laboratory of Retroviral Immunology at the Francis Crick Institute, London, UK. He is also a Professor of Retrovirology, at the Department of Medicine, Imperial College London, UK, and recipient of a New Investigator Award from the Wellcome Trust, UK. His doctoral studies, with Lesley Probert and George Kollias at the Hellenic Pasteur Institute, Athens, Greece, focused on transgenic mouse models for human neuroimmunological diseases. He carried out postdoctoral studies with Brigitta Stockinger at the Medical Research Council's National Institute for Medical Research (NIMR) in Mill Hill, London, UK, on T cell homeostasis and immunological memory. He set up his laboratory at the former NIMR, which later became part of the Francis Crick Institute, London, UK. His laboratory's current work, concentrates on innate and adaptive immune responses to endogenous and exogenous retroviruses.