In agreement with these proinflammatory properties, preclinical and clinical studies by ourselves and others have indicated that MIF is implicated in the pathogenesis of autoimmune diseases, including rheumatoid arthritis (RA), type 1 diabetes, and multiple sclerosis and Guillain-Barré syndrome [5,6,7,8,9,10,15,16]. Here, MIF is linked to rheumatoid arthritis.