MTOR and neoplasm: It is well known that phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT)/mammalian target of rapamycin (mTOR)/ribosomal protein S6 kinase 1 (S6K1) and mitogen-activated protein kinase (MAPK) signaling cascades play an important role in many physiological processes of tumor cells, including cell proliferation, survival, angiogenesis, and metastasis of tumor cells.