They are particularly effective in cancers characterized by BRCA1/2 mutations, which already have compromised homologous recombination repair mechanisms.294 PARP inhibitors such as olaparib, rucaparib, and niraparib have been approved for the treatment of ovarian and breast cancers with BRCA mutations, and their use is expanding to other cancers and settings.295. Here, BRCA1 is linked to cancer.