PTEN and glioblastoma: Researchers identified critical genomic mutations responsible for GBM progression: the PI3K pathway (PIK3CA, PIK3R1, PTEN, EGFR, PDGFRA, and NF1), the Rb pathway (CDK4, CDK6, CCND2, CDKN2A/B, and RB1) and the p53 pathway (MDM2, MDM4, and TP53) [97,98].