MTOR and glioblastoma: We have studied inhibitors of the phosphatidylinositol 3-kinase (PI3K)/Akt/mammalian target of rapamycin (mTOR) pathway as potential radiosensitizers for GBM-SCs because this pathway is important for cell survival–particularly under stress including that induced by γ-irradiation (γIR); moreover, it coregulates stemness in normal stem cells and CSCs [10–15].