The downregulation of hepatic mRNA and protein expression of A1AT was further validated in various preclinical models, including the FFD, high-fat diet (HFD), methionine- and choline-deficient diet (MCD), MCD–HFD, choline-deficient amino acid-defined high-fat diet (CDA–HFD), diabetic obese and liver disease progression aggravation diet-induced MASH models (Fig. 1j and Supplementary Fig. 2b-e). This evidence concerns the gene SERPINA1 and liver disorder.