CellSource Co., Ltd. (TSE Prime: 4880) is a biotech company specializing in regenerative medicine. The company’s origin dates back to 2014, when the Japanese government enacted the Act on Securing Safety of Regenerative Medicine (Safety Act). Formerly employed by a Japanese trading company, Masato Tsumamoto (now representative director and CEO) joined forces with fellow triathlete and cosmetic surgeon Masayuki Yamakawa (now a director and controlling shareholder), to co-found CellSource in November 2015.