IL4 and Autoimmunity: IL-10 is capable of inhibiting the synthesis of proinflammatory cytokines, while IL-12 is linked to autoimmunity by stimulating the production of interferon-gamma (IFN-γ) and tumor necrosis factor-alpha (TNF-α) from T and natural killer (NK) cells, and by reducing IL-4-mediated suppression of IFN-γ.