Dr. Winchester has had a sustained interest in human autoimmunity. His earlier studies defined the molecular importance of rheumatoid factors, other autoantibodies and immune complexes in human disease. Moreover, Dr. Winchester was involved in the early identification and tissue expression of human MHC class II molecules.His earlier studies defined the molecular importance of IgG rheumatoid factors in rheumatoid arthritis and other autoantibodies in various human autoimmune diseases. He also introduced the use of F(ab')2fragments into cell surface immunofluorescence.He received Crafoord Prize in 2013 for their discoveries concerning the role of different genetic factors and their interactions with environmental factors in the pathogenesis, diagnosis and clinical management of rheumatoid arthritis.