Here we identified increased KCTD17 levels in patients with MASH, and in dietary rodent models of MASH—such as those fed a diet high in palmitate, sucrose and cholesterol coupled with fructose-containing drinking water or a choline-deficient, l-amino acid-defined, high-fat diet—which showed an inverse correlation with the expression of serine protease inhibitor a3k (SERPINA3 in humans, Serpina3k in mice). Here, SERPINA3 is linked to metabolic dysfunction-associated steatohepatitis.