Olaparib is the first oral poly-ADP ribose polymerase (PARP) inhibitor used for the treatment of germline breast cancer susceptibility to gene (BRCA)-mutated cancers, such as ovarian cancer.[1] Olaparib inhibits PARP and is involved in several processes including the repair of single-strand DNA breaks, genomic stability, and programmed cell death.[2,3] Olaparib is a therapeutic option for maintenance therapy of ovarian cancer after platinum-based chemotherapy, regardless of the BRCA status.[4]. The gene discussed is PARP1; the disease is cancer.