FASN and metabolic dysfunction-associated steatohepatitis: During de novo lipogenesis, acetyl-CoA-carboxylase (ACC) and fatty acid synthase (FASN) convert metabolites of dietary sugars into the fatty acid palmitate, which is a key regulatory factor of lipid accumulation and lipotoxic substances, contributing to the pathogenesis of NASH (Loomba et al., 2021a).