The 2011 Nobel Prize in Physiology or Medicine has been awarded to National Institutes of Health grantees Bruce A. Beutler, M.D., of The Scripps Research Institute, La Jolla, Calif.; and Jules A. Hoffmann, Ph.D., for their discoveries concerning the activation of innate immunity and the late Ralph M. Steinman, M.D., of Rockefeller University, New York City for his discovery of the dendritic cell and its role in adaptive immunity.