In cell culture, it has been demonstrated that both peroxisome proliferator-activated receptor α (PPARα) agonists and estradiol induce PDZK1 protein expression in a human hepatoma cell line and in an ovarian cancer cell line, respectively[41] [42], and consensus sequences for a peroxisome proliferator responsive element and an estrogen responsive element have been identified in the human PDZK1 promoter[41]. This evidence concerns the gene PPARA and hepatocellular carcinoma.