The indirect biomarkers consist of biochemical analysis of serum and the clinical parameters of patients, including the aspartate aminotransferase (AST)-alanine aminotransferase (ALT) ratio, the AST–platelet ratio index (APRI), FIB-4 (evaluation of fibrosis based on age, AST, ALT and platelet count), Fibro index (diagnosis based on platelet count, AST and gamma globulin) and Forns index (based on age, platelet count, cholesterol levels and Gamma-glutamyltransferase (GGT)) [73,74,75,76,77]. The gene discussed is GPT; the disease is fibrosis.