Dr. Shigeo Koyasu received his D.Sc. degree from the University of Tokyo (1983). After serving as Research Associate at the Tokyo Metropolitan Institute of Medical Science (1981-1988), he moved to Harvard and served as Instructor (1988-1990), and Assistant Professor of the Department of Pathology, Harvard Medical School (1990-1995), and Associate Professor of Medicine, Harvard Medical School (1995-1996). He moved back to Japan in 1995 and was appointed Professor and Chairman of Microbiology and Immunology, Keio University School of Medicine (1995-2013). He then served as Director of RIKEN Center for Integrative Medical Sciences (IMS) and is currently Executive Director of RIKEN. In academic societies, he has served as a board member of the Japanese Society for Immunology (JSI) and the Molecular Biology Society of Japan (MBSJ). Internationally, he has served as Council member of the International Union of Immunological Societies (IUIS), Treasurer of the Federation of Immunological Societies of Asia and Oceania (FIMSA), and President of FIMSA. The most important contribution of his research group to the field of immunology was the discovery of the group 2 innate lymphoid cells (ILC2), which is an innate lymphocyte population critical for early responses against worm infection and pathophysiology of allergic inflammation.