Our analysis on sera of NAFLD patients showed that: (i) circulating V10 is overexpressed in NASH patients compared to NAFL patients and positively correlates with NAS; (ii) circulating V75 is underexpressed in NASH patients compared to NAFL patients and negatively correlates with NAS and liver fibrosis; (iii) the V10/V75 ratio is a predictor of NAS score, independently from BMI, ALT, and AST; (iv) circulating V10 originates from the disulfide bond reduction of the V75 clipped form. The gene discussed is GPT; the disease is metabolic dysfunction-associated steatohepatitis.