Suppression of the base excision and repair pathway by PARP inhibitors in BRCA2-deficient/HR-defective cancer cells has a synthetically lethal effect, because it generates an overwhelming genomic instability that fosters cancer cells to death [21], thus making PARP inhibitors promising candidates for the treatment of BRCA2-deficient castration-resistant prostate cancers. The gene discussed is BRCA2; the disease is Familial prostate cancer.