Bruce Alan Beutler is an American immunologist and geneticist. Together with Jules A. Hoffmann, he received one-half of the 2011 Nobel Prize in Physiology or Medicine, for "discoveries concerning the activation of innate immunity." Beutler discovered the long-elusive receptor for lipopolysaccharide. He did so by identifying spontaneous mutations in the gene coding for mouse Toll-like receptor 4 (Tlr4) in two unrelated strains of LPS-refractory mice and proving they were responsible for that phenotype. Subsequently, and chiefly through the work of Shizuo Akira, other TLRs were shown to detect signature molecules of most infectious microbes, in each case triggering an innate immune response. The Nobel Prize in Physiology or Medicine 2011, announced October 3, 2011. Bruce A. Beutler (1/4), “for their discoveries concerning the activation of innate immunity”. Jules A. Hoffmann (1/4), “for their discoveries concerning the activation of innate immunity”. Ralph M. Steinman (1/2), “for his discovery of the dendritic cell and its role in adaptive immunity”. Bruce A. Beutler: born 1957, Chicago, IL, USA. Jules A. Hoffmann: born 1941, Echternach, Luxembourg. Ralph M. Steinman: born 1943, Montreal, Canada. Wiki link Wiki link Wiki link Data: the Nobel Foundation (CC0).