IL6 and Autoimmunity: Mice deficient of Regnase-1 exhibit severe autoimmune disorders characterized by augmented serum immunoglobulin and autoantibody levels, splenomegaly and pulmonary inflammation.142 Mechanistically, Regnase-1 recognizes the stem loop in mRNAs encoding proinflammatory cytokines, such as IL-6, to mediate mRNA decay with its RNase activity.