1985—1991 M.D. Seoul National University College of Medicine 1999—2001 Ph.D. in Medicine, Seoul National University Graduate School 2000—2006 Chief, Department of Nuclear Medicine, Hospital, National Cancer Center, Korea 2003—2004 Visiting Scientist, Molecular Imaging Program at Stanford University, U.S.A. 2007—present. Professor, Department of Nuclear Medicine, Seoul National University College of Medicine, Korea 2013—2021 Member, Committee 3 (Medicine), International Commission on Radiological Protection 2020—present. Chair, Medical Applications Special Committee, World Council on Isotope 2022—2024 President, the Korean Society of Nuclear Medicine 2022—present. Chairman, Asian Regional Cooperative Council for Nuclear Medicine 2023—2024 Commissioner, Bio-MAX Institute, Seoul National University 2024—present. Head, Center for Entrepreneurship and Innovation, Seoul National University 2024—present. Associate Editors (International), Journal of Nuclear Medicine 2024—present. Commissioner, Nuclear Safety and Security Commission, Korea 2026—present. President, the Korean Association for Radiation Protection 2026—present. Member, National Academy of Engineering of Korea 2026—present. Vice President, Korean Federation of Science and Technology Societies