In order to evaluate whether the new epigenetic agent RRx-001, that induce DNA damage through the release of reactive oxygen or nitrogen species, combined with P5091, that downregulates CCDC6 and impairs HR-DNA repair, might increase the sensitivity to PARPi in urothelial carcinoma cells, we treated the bladder cancer cells with different concentrations of the PARP-inhibitor Olaparib and with fixed doses of P5091 and RRx-001. The gene discussed is CCDC6; the disease is urinary bladder cancer.