Maintenance therapy with poly (ADP-ribose) polymerase inhibitors (PARPi, such as Olaparib) is the most advanced regimen for ovarian cancer treatment and is used primarily for patients with BRCA1/2 mutations or homologous recombination deficiency (HRD), with its success corroborated by several phase III clinical trials1. The gene discussed is BRCA1; the disease is ovarian cancer.