In conclusion, rescuing bone resorption in Msx2−/− mice by overexpressing RANK in the osteoclastic lineage allowed for the correction of a substantial portion of the molar abnormalities, most likely by counteracting the decrease in RANKL expression, which is correlated with Msx2−/− osteopetrosis. The gene discussed is TNFSF11; the disease is osteopetrosis.