ACOX1 and hydrops fetalis: The HF group also exhibited a decrease in the expression of genes that are known to be regulated by peroxisome proliferator-activated receptor- α (Ppara), such as acyl-CoA oxidase (Acox) and medium chain acyl-coenzyme A dehydrogenase (MCAD) enzymes, which catalyze the key steps in peroxisomal and mitochondrial β-oxidation, respectively.