It is now well established that cancers that exhibit pathogenic variants in BRCA1 or BRCA2 respond well to treatment with PARPi (Bryant et al., 2005; Farmer et al., 2005), a therapeutic strategy that has emerged for BRCA1- and BRCA2-mutated breast and ovarian tumors (Audeh et al., 2010; Tutt et al., 2010; Lord and Ashworth, 2017). The gene discussed is BRCA1; the disease is cancer.