Moreover, in animal models for inflammatory arthritis such as adjuvant-induced arthritis, collagen-induced arthritis, and antigen-induced arthritis (AIA), it was clearly shown that MIF was involved in the pathogenesis of inflammatory arthritis, and the development and severity of the arthritis and the infiltration of inflammatory cells into joint tissues were significantly suppressed by administration of an anti-MIF polyclonal antibody [20, 38, 57, 77], suggesting that MIF may be functionally active during the development of arthritis. The gene discussed is MIF; the disease is arthritic joint disease.