Ichimura et al. reported that among 120 GBM, 40% had no wild-type CDKN2A gene, 12% amplified the CDK4 gene, and 14% had no wild-type RB1 gene [47], and the majority of the GMB (64%) had only one of these abnormalities [48]. This evidence concerns the gene CDK4 and glioblastoma.