In lupus patients, Th1-induced anti-DNA IgG1antibodies are always elevated before the occurrence of renal relapse, and IgG1 plus IgG2 anti-DNA antibodies are found in patient’s renal eluates, whereas in lupus prone mice, murine Th1-induced IgG2a, IgG2b, and IgG3 anti-DNA are more frequently eluted from kidneys with active nephritis (39, 42, 86–88). The gene discussed is IGHG3; the disease is systemic lupus erythematosus.