TNFSF11 and rheumatoid arthritis: In addition, we evaluated TNFSF11 (TNFSF11, TNF Superfamily Member 11 or Receptor activator of nuclear factor kappa-B ligand, RANKL) and TNFRSF11B (TNF Receptor Superfamily Member 11b, or Osteoprotegerin, OPG) expression, because disturbed RANKL/OPG ratio promotes osteoclastogenesis and bone damage in RA (38).