Stanley Cohen, 1922–, American biochemist, b. New York City, Ph.D. Univ. of Michigan, 1948. Cohen did his most important work at Washington Univ. with Rita Levi-Montalcini in the 1950s. Studying mouse tumors implanted in chicken embryos, the pair isolated a nerve growth factor, the first of many cell growth factors found in animals; some of these were also first described by Cohen and by Levi-Montalcini. Their discovery of nerve growth factor radically changed the study of cell growth and development. For this discovery Levi-Montalcini and Cohen were awarded the 1986 Nobel Prize in Physiology or Medicine. In 1959 Cohen moved to Vanderbilt Univ., where he became a professor.