Four inhibitors of PARP (olaparib, talazoparib, rucaparib, and niraparib) have been approved for the treatment of cancers associated with BRCA1 and BRCA2 mutations (95) as PARPi were found to be specifically lethal to BRCA1/2-deficient cells, following the principle of synthetic lethality (96, 97). The gene discussed is PARP1; the disease is cancer.