MTOR and glioblastoma: Multiple signaling pathways, such as the Wnt signal, the phosphatidylinositol 3-kinase (PI3K)/Akt/mammalian target of rapamycin (mTOR) axis, and the programmed death (PD)-1 and PD-ligand 1 (PD-L1) axis, are reported to participate in regulating the proliferation of human glioblastoma cells [4,5].