AFP and hepatocellular carcinoma: ALT = alanine aminotransferase; AST = aspartate aminotransferase; GGT = gamma-glutamyl transferase; ALP = alkaline phosphatase; LDH = lactate dehydrogenase; AFP = alpha-fetoprotein; HBsAg = hepatitis B surface antigen; CEA = carcinoembryonic antigen; CA 19-9 = carbohydrate antigen 19-9); SOD = superoxide dismutase; GSH = glutathione; MDA = malondialdehyde; TOS = total oxidant status; TAS = total antioxidant status; OSI = oxidative stress index; HCC = hepatocellular carcinoma