FCGR2A and inflammatory bowel disease: The potential involvement of IgG and FcγRs in IBD pathogenesis was highlighted by the consistent identification of an activating Fcγ receptor gene variant, FCGR2A-R/H131, among associated risk loci in UC across genome wide association (GWA) studies in multiple populations.20,23 Specifically, the FCGR2A variant rs1801274 encoding a receptor with low affinity for IgG (R131) is associated with protection from UC,23 suggesting a pathogenic role for IgG.