MTOR and neoplasm: Molecularly, GB have been associated with alterations in cell cycle regulatory genes such as p16, cyclin-dependent kinase (cdk) 4, cdk6, cyclin D1 and retinoblastoma protein, as well as of molecules belonging to tumor activation pathways like receptor tyrosine kinases responsible for activation of the Phosphoinositide 3-kinases (PI3K), Protein kinase B, (Akt), mammalian target of rapamycin (mTOR) and mitogen-activated protein kinase (MAPK) axes [21].