The prevalence of mutations in the RB and TP53 genes, though important drivers in many tumors, illustrates again that GBM is highly heterogeneous and depends on many distinct alterations: RB is mutated in only 6–11% of GBM cases and 27–33.8% of GBM bear mutations in the TP53 gene [40,97]. This evidence concerns the gene RB1 and glioblastoma.