A high dose of indomethacin produced more severe intestinal ulcers and enhanced gastro-intestinal permeability defect (gut leakage) in 24-wk-old FcgRIIb-/- mice compared to wild-type (WT) mice suggesting a prominent adverse effect of NSAIDs in lupus. This evidence concerns the gene FCGR2B and systemic lupus erythematosus.