In addition, high levels of phosphorylated AKT (p-AKT) and phosphorylated GSK3β (Tyr216) were correlated to a poor prognosis in glioblastoma, and silencing of GSK3β induced cell apoptosis and increased the levels of the tumor suppressors p53 and p21[30, 31]. This evidence concerns the gene TP53 and glioblastoma.