ACOX1 and hepatocellular carcinoma: In line with these findings, overexpression of CtBP2 in HepG2 cells, a human hepatoma cell line, reduced the expression levels of PPARα target genes at baseline compared to the overexpression of a control protein, glucuronidase (GUS), albeit to a moderate extent (Fig. 1C, 30% and 15% for acyl-CoA oxidase 1 [ACOX1] and PPARA, respectively).