CDK4 and central nervous system cancer: GISTIC 2.0 analysis revealed that in gliomas with high-risk scores, the amplification mainly occurred in chromosomal regions 1q32.1, 3q26.33, 4q12, 7p11.2, and 12q14.1, where several key oncogenes (PDGFRA, EGFR, MDM2, SOX2, and CDK4) were located.