Although HCCs are phenotypically and genetically heterogeneous tumors, several signaling pathways such as the Ras/Raf/MEK/ERK (MAPK) pathway, the phosphoinositol 3-kinase (PI3k)/Akt/mammalian target of rapamycin (mTOR) pathway, and the Wnt/beta catenin pathway have been repeatedly identified as important for HCC cell proliferation and angiogenesis. The gene discussed is MTOR; the disease is hepatocellular carcinoma.