CDK4 and glioblastoma: However, from all these genes listed in table 2, only AVIL, FAM119B, METTL1, CYP27B1 and TSFM were systematically amplified in tumors displaying 12q amplicons..Co-amplification of the CDK4 and MDM2 genes at the 12q13–15 amplicon is frequently observed in GBM and it has been previously suggested to confer a tumor growth advantage [42].