We have previously shown that the pathogenic effect of anti-COL2 antibodies is downregulated by FCGR2B, and we confirmed this also in BQ.Col2266E mice, which is much more susceptible to collagen antibody-induced arthritis (CAIA) if deficient in Fcgr2b (Fig. 2c). The gene discussed is FCGR2B; the disease is arthritic joint disease.