TGFB1 and cirrhosis of liver: To give an insight on the molecular factors underlying the evolution of liver cirrhosis to HCC, we evaluated the association between the genetic variations in two pro-fibrogenic genes; TGF-β1 and PNPLA3 and the progression of chronic HCV infection, liver cirrhosis development, and HCC risk among patients with HCV infection (Lee and Friedman, 2011; Dongiovanni et al., 2013).