The NFS (composed of BMI, age, presence of T2DM, AST:ALT ratio, platelet count and albumin) was specifically constructed and validated in biopsy-proven NAFLD (34, 37, 55), whereas the FIB-4 algorithm (composed of AST, ALT, platelet count and age) was originally derived for use in hepatitis C/HIV coinfection and later effectively validated in NAFLD (35, 56). The gene discussed is GPT; the disease is hepatitis C virus infection.