suggest that the PPARα-FGF21 axis regulates hepatic lipid metabolism, and it is due to the failed induction of the PPARα-FGF21 axis that Cyp2a5−/− mice develop more severe alcoholic fatty liver. In Cyp2a5+/+ mice, ethanol induced a compensatory upregulation of the PPARα-FGF21 axis, which regulates hepatic lipid metabolism and blunts the development of fatty liver disease. When the PPARα-FGF21 axis was not upregulated as compensation, the fatty liver was more pronounced as seen in the Cyp2a5−/− mice.
