MTOR and glioblastoma: Rapamycin and its analogs have demonstrated efficacy in GBM by inhibiting the mTOR pathway and inactivating the vital downstream kinases, the p70S6 kinase and the eukaryotic initiation factor 4E binding protein-1(4E-BP-1) [28]; however, most clinical trials using inhibitors of the components in this pathway as monotherapies have failed to demonstrate survival benefit in glioblastoma patients [29].