41 Tumors with HR deficiencies arising from sporadic mutations or silencing of genes that are essential for HR have been termed BRCA-like.42 Not only are BRCA-like tumors associated with PARP inhibitor sensitivity, but they have also been shown to have better response to platinum therapeutics such as cisplatin.24 Importantly, with nearly a quarter of a million new cases of breast cancer in the United States annually,43 this 20% of responding patients with wild-type BRCA1/2 represents nearly 50,000 patients, four-fold more than the sum of all BRCA1/2-mutation carriers. Here, BRCA1 is linked to breast cancer.