PPARA and metabolic dysfunction-associated steatotic liver disease: Studies of mitochondrial cytochrome P4502E1 (mtCYP2E1), in wild-type and PPAR α-deficient mice fed either a standard diet or a high-fat diet (HFD), have shown that the highest levels of hepatic mtCYP2E1 have been found in PPAR para-deficient HFD mice, which exhibit the highest NAFLD activity scores (NAS) of all animal groups.