MTOR and hepatocellular carcinoma: For example, an additive and synergistic effect of targeting the Ras/Raf/MAPK pathway in combination with other pathways important in HCC proliferation such as Phosphatidylinositol-4,5-bisphosphate 3-kinase (PI3K)/AKT/ mammalian target of rapamycin (mTOR) and Wnt/β-catenin has been shown [4].