PNPLA2 and metabolic dysfunction-associated steatohepatitis: Collectively, these findings demonstrate that targeted mutation of the Ser33 residue in 17β-HSD13 accelerates HFD-induced NASH mainly via the suppression of ATGL-mediated LD lipolysis, with little impact on the expression of genes involved in hepatic lipid metabolism and whole-body energy homeostasis in mice.