IL2 and rheumatoid arthritis: Interestingly, significantly increased percentages of sera from rheumatoid arthritis (RA), Sjögren syndrome, systemic lupus erythematosus and autoimmune myositis patients were also anti-rhIL-2-autoantibodies+, and anti-mIL-2 autoantibodies were found in lupus-prone mice (Fig. 6); indicating that IL-2 autoreactivity plays a previously unsuspected role in the pathogenesis of different autoimmune conditions in human and mouse.