Intern in medicine medical division III Bellevue Hospital, New York City, 1958—1959, assistant resident in medicine medical division III, 1959—1960. National Foundation fellow department microbiology College Physicians Columbia University, 1960—1962. Assistant physician medical service Vanderbilt Clinic, College Physician United States Public Health Service, Washington, 1960—1962.
Ward hematology fellow department internal medicine School Washington University, St. Louis, 1962—1963. Research associate laboratory biochemistry National Cancer Institute United States Public Health Service, Washington, 1963—1965. Clinical instructor in medicine School of Medicine George Washington University, 1964—1965.
Associate in medicine, director blood bank Beth Israel Hospital, Boston, 1965—1966. Instructor Medical School Harvard University, 1966—1968, assistant physician, 1967—1968, chief clinical immunology, 1971—1973. Physician Beth Israel Hospital, since 1968.
From assistant to associate professor medicine Harvard Medical School, 1968—1977, professor, since 1977, Baruj Benacerraf professor medicine, since 1990, chief division tumor immunology and immunotherapy, since 1973. Senior physician Brigham and Women's Hospital, since 1976.
Member editorial board Journal of Immunology, 1969-1974, Cellular Immunology, since 1970, Human Immunology, 1979-1984, Clinical Immunology and Immunopathology, since 1979, member editorial bd. Hybridoma Hybridoma, since 1980, Cancer Investigation, since 1981, Stem Cells, since 1981, Cancer Revs., 1984, International Journal of Cell Cloning, 1983-1986, member advisory board Cancer Treatment Reports, 1976-1980, associate editor Human Lymphocyte Differentation, 1980-1982.
Contributor articles to professional journals.
Fellow: American Association for the Advancement of Science. Member: National Academy of Sciences, Association American Physicians, American Society Clinical Investigation, American Society Immunologists, American Society Hematology, Institute of Medicine of National Academy of Sciences, Alpha Omega Alpha.