FGF21 and fatty liver disease: Collectively, the anti-steatosis effect of PPARα may be partly related to up-regulation of its target genes CYP4A10 and CYP4A14, induction of SIRT1 axis by up-regulation of FGF21 and adiponectin expression, as well as down-regulation of FAS and PI3K expression, which ameliorated hepatic steatosis induced by ethanol consumption.