BRCA1 and ovarian cancer: We previously identified KJ-28d as a novel PARP inhibitor that leads to increased cytotoxicity in human ovarian cancer BRCA-1-deficient SNU-251 (BRCA1 mutation at 5564G>A) cells, as well as in triple-negative human ovarian cancer BRCA1 heterozygous (BRCA1+/−) MDA-MB-231 cells [21].