Fcgr2b−/− mice positive for IgG autoAbs started to develop proteinuria by the age of 6 months, and about a half of the Fcgr2b−/− mice died due to severe nephritis by the age of 9 months (Figures 1A,B and data not shown) (46, 49, 50). The gene discussed is FCGR2B; the disease is nephritis.