MTOR and glioblastoma: It arrests the cell cycle at the G0-G1 phase to inhibit the multiplication of human glioblastoma cells by enhancing the expression of p27 and reducing that of cdk2, cdk4, cdk6, cyclin D and cyclin E, and inhibiting the signaling of phosphatidylinositol 3 kinase/protein kinase B/mammalian target of rapamycin (PI3K/AKT/mTOR).