To identify small molecule drugs that can synergize with PARPi for breast cancer cells, the 92 J isogenic pair of cell lines was used to screen the NPC library in the absence or presence of AG14361 at a concentration that killed 50% (IC50) of cells (92 J-wt-BRCA1, 17 μM, 92 J-sh-BRCA1, 25 μM, respectively). This evidence concerns the gene BRCA1 and breast cancer.