Further, in autoimmune models of experimental autoimmune encephalomyelitis, arthritis, colitis, myocarditis, and diabetes in which T cells may play a significant role, STAT4 deficiency demonstrated a reduction in autoimmune manifestations associated with reduced IFN-γ production and a switch from a dominant IgG2a response to IgG1 (12). The gene discussed is IFNG; the disease is arthritic joint disease.