Among patients with BRCA1/2-mutant breast cancer, dramatic initial responses to PARPi drugs, such as olaparib and talazoparib, led to their FDA approval as monotherapy (Comen and Robson, 2010; D’Andrea, 2018; Litton et al, 2018; Robson et al, 2017). This evidence concerns the gene BRCA1 and breast carcinoma.