TP53 and cancer: We further confirmed this effect in another pair of cancer cell lines (PC3 and PC3 MDM2 KD) with different p53 status (p53 null) (Fig. 7), removal of MDM2 also inhibited the effects of 25-OCH3-PPD, including cell survival (Fig. 7A), cell proliferation (Fig. 7B), apoptosis (Fig. 7C), and G1 cell cycle arrest (Fig. 7D).