Receptoractivatorofnuclearfactorkappa-Bligand(RANKL),alsoknownastumornecrosisfactorligandsuperfamilymember11(TNFSF11),isaproteinthatinhumansisencodedbytheTNFSF11gene.Thisgeneencodesamemberofthetumornecrosisfactor(TNF)cytokinefamilywhichisaligandforosteoprotegerinandfunctionsasakeyfactorforosteoclastdifferentiationandactivation.Thisgeneismappedtochromosome13q14.11.Targeteddisruptionoftherelatedgeneinmiceledtosevereosteopetrosisandalackofosteoclasts.ThedeficientmiceexhibiteddefectsinearlydifferentiationofTandBlymphocytes,andfailedtoformlobulo-alveolarmammarystructuresduringpregnancy.Thisgenemayplayanimportantroleinenhancedbone-resorptioninhumoralhypercalcemiaofmalignancy.