SPP1 and osteosarcoma: Other genes that showed deregulated expression and significant contribution to osteosarcoma gene networks included overexpressed SPP1, IBSP, BMP2, and c-MYC, and uderexpressed CDKN1A, LSAMP, and CCNB1. Another gene that is thought to play a role in osteosarcoma and has been shown to be overexpressed is the FOS proto-oncogene [20,21].