Patients with hepatitis B (HBV) were more likely to develop HCC at a younger age than patients with hepatitis C (HCV) (HBV-26% under age 40, HCV-0% under age 40; p < 0.001), with greater serum alpha-Fetoprotein production (median level: HBV-1000 ng/ml vs. HCV-37 ng/ml; p = 0.002), with larger tumors (HBV-78% >5 cm, HCV-28% >5 cm; p < 0.001), in the absence of cirrhosis (HBV-40%, HCV-0%; p < 0.001), and a decreased eligibility for curative treatment (HBV-14%, HCV-34%; p < 0.05). The gene discussed is AFP; the disease is hepatocellular carcinoma.