EP300 and prostate carcinoma: Interestingly, decreased cell viability also occurred after treatment with a p53 acetylation inhibitor in p53 mutant DU145 cells (for reference, Hep3B cells are p53 null) which showed no increase of p53 acetylation with Daxx downregulation (Fig. 4F), possibly through p300 inhibition acting like an inducer of apoptosis in prostate cancer cells39.