MTOR and central nervous system cancer: Numerous studies have disclosed the high frequency of genetic aberrations in glioma, including the tumor protein p53 (TP53) [45, 46], cyclin-dependent kinase inhibitor 2A/B (CDKN2A/B) [47–49], tensin homolog (PTEN) [50, 51], EGFR [52, 53], PDGFRA [54], and PIK3CA, which leads to dysregulation of downstream signaling pathways such as the RB transcriptional corepressor 1 (RB1), PI3K/Akt/mTOR, and p53 [55–57].