To test whether modulation of the identified pathway could be used to intervene in the progression of steatosis, we first analysed hepatic lipid metabolism after knocking out Acox1 and Pex2. We observed upregulation of liver lipolysis, whereas global FA oxidation, TG secretion, FA uptake and esterification remained unaltered (Extended Data Fig. 9s–w). This evidence concerns the gene ACOX1 and steatosis.