PARP1 and ovarian carcinoma: When PARP inhibitors and BET inhibitors are used together, tumors that are proficient in homologous recombination may become more sensitive to the PARP inhibitors and may eventually acquire resistance to them.596,597 Clinical investigations have been prompted by the synergistic benefits between PARP and BET inhibition observed in preclinical studies, particularly in breast and ovarian cancers.