The process of tumor osteolysis has been associated with changes in the levels of RANK-L and OPG in multiple myeloma, osteosarcoma, osteoblastic metastasis of prostate carcinoma, giant cell lesions, and interestingly, in some odontogenic tumors, such as ameloblastoma, odontogenic keratocyst and calcifying epithelial odontogenic tumor (18,23,25). The gene discussed is TNFSF11; the disease is osteosarcoma.