CHI3L1 and metabolic dysfunction-associated steatohepatitis: In this study, we determined the source and contribution of CHI3L1 on NASH development through cellular and molecular mechanisms by using various in vivo and in vitro approaches including a human-relevant male murine model of progressive fibrotic NASH choline-deficient, L-amino acid-defined, high-fat diet (CDAA-HFAT) and genetically modified mice with cell-specific deletion of the CHI3L1 gene.