Tomonori MIZUTANI M.D., Ph.D. is a medical oncologist and an Assistant Professor at Kyorin University Faculty of Medicine, Japan. He has engaged in educational activities on geriatric oncology; he is a chair of the Japan Geriatric Oncology Society and a member of Geriatric Committee of the Japan Geriatrics Society and the Japanese Society of Medical Oncology. He also puts an emphasis on clinical research for older adults with cancer; he is a chair of Non-Profit Organization Clinical Oncology Research and Education and is also an executive officer of the Geriatric Study Committee of the Japan Clinical Oncology Group (JCOG), which the largest cooperative group in Japan and has handled several clinical researches focusing on older patients with cancer. His research interests are improving health and well-being and establishing the robust methodology for older adults with cancer. He, therefore, established a JCOG policy for geriatric cancer research, which described the methodology of clinical research for older patients with cancer (Tomonori M. Jpn J Clin Oncol. 2019 Sep 30.). Moreover, he is the national representative from Japan in SIOG and has developed the SIOG Global Clinical Practice Working Group to promote the further development of geriatric oncology on a global scale.