Simon Flexner
American physician and scientist (1863–1946)
Simon Flexner was an American physician, scientist, administrator, and professor of experimental pathology at the University of Pennsylvania (1899–1903). He served as the first director of the Rockefeller Institute for Medical Research (1901–1935) and a trustee of the Rockefeller Foundation. He was also a friend and adviser to John D. Rockefeller Jr.