KRAS and hepatocellular carcinoma: Several groups have studied the molecular mechanisms by which HCV induces liver fibrosis and have reported the following: (i) HCV core protein activates the TGF-β1 promoter via the MAPK pathway in core protein-expressing human hepatocellular carcinoma HepG2 cells11; (ii) recombinant core protein upregulates the expression of fibrogenic genes in the human hepatic stellate cell line LX-2 via the toll-like receptor 2 12 and the obese receptor13; and (iii) NS3 protease induces TGF-β1 production in NS3-overexpressing human hepatoma Huh-7 cells14.