We have shown that mice lacking mature B cells are fully resistant against G6PI-induced arthritis [7]; in mice lacking the FcγR common gamma chain G6PI-induced arthritis occurs at a very low incidence and strongly reduced severity, whereas G6PI-induced arthritis is more severe and chronic in mice lacking the inhibitory FcγRIIB [6]. This evidence concerns the gene FCGR2B and arthritic joint disease.