Steinman, Ralph Marvin, 1943–2011, Canadian biologist, M.D. Harvard Medical School, 1968. He was a researcher and professor at Rockefeller Univ., New York City, from 1970 until his death in 2011. Steinman was awarded half of the 2011 Nobel Prize for Physiology or Medicine for his discovery in 1973 of the dendritic cell and its role in adaptive immunity; he shared the prize with Bruce A. Beutler and Jules A. Hoffmann. Steinman showed that dendritic cells can sense signals from the body's innate immune response and then activate T lymphocytes, or T cells, a type of blood cell that protects the body from infection. This mechanism allows the immune system to fight off foreign pathogens without attacking the body's own cells. Steinman was diagnosed with pancreatic cancer in 2007, and he extended his own life using a dendritic-cell-based immunotherapy that he designed himself.