HCV, Hepatitis C virus; HCC, hepatocellular carcinoma; IFN-γ, interferon-gamma; TNF-α, tumor necrosis factor-alpha; PCR-RFLP, polymerase chain reaction-restriction fragment length polymorphism; AFP, alpha-fetoprotein; AST, aspartate aminotransferase; ALT, alanine aminotransferase; PT, prothrombin time; TG, triglycerides; INR, international normalized ratio; CBC, complete blood count. The gene discussed is TNF; the disease is hepatocellular carcinoma.