PTEN and glioblastoma: According to the TCGA data for GBM patients, approximately 90% of patients have alterations in the PI3K/MAPK pathway: Epidermal Growth Factor Receptor (EGFR), Platelet-derived Growth Factor Receptor Alpha (PDGFRA), and PI3K genes are frequently amplified or mutated to gain function (approximately 57, 10 and 25%, respectively), while Phosphatase and Tensin Homolog (PTEN) is deleted or mutated in 41% of patients [11].