Poly(ADP-ribose) polymerase (PARP) inhibitors target DNA repair pathways and are particularly effective in cells that have impaired homologous recombination (HR) pathway. Ovarian cancer cells with BRCA mutation have deficiency in the HR pathway and this defect is also seen in a significant proportion of non-BRCA-mutated ovarian cancer. Thus PARP inhibitors like Olaparib and Rucaparib appear promising in the treatment of ovarian cancers. References:Ledermann JA. PARP inhibitors in Ovarian Cancer. Ann Oncol. 2016 Apr;27 Suppl 1:i40-i44. Dziadkowiec KN et al. PARP inhibitors: review of mechanisms of action and BRCA1/2 mutation targeting. Menopause Rev 2016; 15(4):215-219.