POR and hepatocellular carcinoma: Interestingly, we recently showed that the results observed in HRN mice could be recapitulated in cultured mouse hepatoma Hepa1c1c7 cells that carried a gene knockout in POR (i.e. POR KO Hepa1c1c7 cells) [14], in which, BaP-DNA adduct levels were approximately 10-fold higher in POR KO Hepa1c1c7 cells than in WT Hepa1c1c7 cells following exposure to BaP.