Answer
Baruj Benacerraf was a Venezuelan-born American immunologist who, together with Jean Dausset and George Davis Snell, was awarded the Nobel Prize in Physiology or Medicine in 1980 for their discovery of the major histocompatibility complex. The MHC is a group of genes that code for proteins that are expressed on the surface of cells and play a role in the immune system's ability to distinguish between self and non-self.