Guenter Steiner is Professor of Biochemistry and Immunology at the Department for Rheumatoology of the Medical University of Vienna and director of the Ludwig Boltzmann Institute forArthritis and Rehabilitation. His research activities are focused on elucidating the pathomechanisms of systemic autoimmune diseases, with a strong focus on rheumatoid arthritis (RA). Investigations are aimed on the one hand at understanding roles of T cells and synovial fibroblasts in the the pathogenesis of RA, and on the other hand on the role and diagnostic value of autoantibodies in RA and other systemic autoimmune diseases. As director of the Ludwig Boltzmann Institute forArthritis and Rehabilitation he is involved in building up a Nation-wide patient registry for osteoarthritis, the most common joint disease. Guenter Steiner is member of the “IUIS/WHO/AF/CDC Committee for the Standardization of Autoantibodies in Rheumatic and Related Diseases” and of the “European Autoimmunity Standardization Initiative”. He has authored about 150 articles in peer-reviewed scientific journals and written more than 20 book chapters.