Since OPN can enhance tumor cell migration, invasion and spread, activate osteoclasts, and protect cells from immune mediated cytotoxicity, the elevated expression of OPN in ameloblastoma tumor cells and peritumor nest connective tissue of ameloblastoma, can, at least, partially explain why MCA have the locally invasive behavior and high osteolytic ability [25]. This evidence concerns the gene SPP1 and ameloblastoma.