TP53 and glioblastoma: Etienne and colleagues demonstrated that older patients, who often have the De Novo (primary) form of GBM, have EGFR overexpression which is responsible for increased angiogenesis, edema, and invasion and might account for the decrease in survival in elderly patients [24]; younger patients more often exhibit a secondary form of glioblastoma that is associated with TP53 mutation [24].