Baruj Benacerraff (born 29 October, 1920) is a Venezuelan-American immunologist who shared the 1980 Nobel Prize in Physiology or Medicine for the "discovery of the Major histocompatibility complex genes which encode cell surface molecules important for the immune system's distinction between self and non-self". Born in Caracas, his parents were Sephardic Jews from the Maghreb. His brother is well-known philosopher Paul Benacerraf.