The aryl hydrocarbon receptor (AhR) pathway critically influences RA immunoregulation, particularly in RANKL-mediated osteoclastogenesis through nuclear factor kappa-light-chain-enhancer of activated B cells/mitogen-activated protein kinase (NF-κB/MAPK) signaling (57, 58). The gene discussed is TNFSF11; the disease is rheumatoid arthritis.