MTOR and cancer: Although the molecular mechanisms whereby autophagy mediates its effects on both normal and cancer cells are far from complete, various signaling pathways have been implicated in the upregulation or downregulation of autophagy.10, 11 The phosphatidylinositol 3-kinase/mammalian target of rapamycin (PI3K/mTOR) and AMP-activated protein kinase (AMPK) signaling pathways have emerged as the central conduit in the regulation of autophagy (Figure 2).