TNFSF11 and systemic lupus erythematosus: We found that IgG inhibited osteoclastogenesis induced by RANKL in a dose-dependent manner, and deficiency of FcγRII and FcγRIII did not influence the inhibitory effect of IgG in the formation of osteoclasts; both IgG from lupus serum and RANKL reduced the level of FcγRI (27).