Scientist, immunologist in particular.
Shared the 1984 Nobel Prize in Medicine for monoclonal antibody technology with Cesar Milstein and Georges J.F. Kohler.
Proponent of the "Idiotype Cascade" idea, where you have antibodies to antibodies. These anti-antibodies also have antibodies. It's a theory to describe how you can get different antibodies that can recognize the same thing, but in a different way. It's a theory that is currently out-of-fashion.