Baruj Benacerraf ( October 29 , 1920 -- August 2 , 2011 ) was a Venezuelan-born 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 protein molecules important for the immune system 's distinction between self and non-self '' .
Baruj Benacerraf ( October 29 , 1920 -- August 2 , 2011 ) was a Venezuelan-born American immunologist . Benacerraf won the Nobel Prize in Physiology or Medicine in 1979 for his `` discovery of the major histocompatibility complex genes which encode cell surface protein molecules important for the immune system 's distinction between self and non-self '' .