Of the 64 PARP inhibitor candidates with TNBC, 12 (18.8%) tested positive for a BRCA1/2 GPV, whereas of 37 PARP inhibitor candidates with ER-positive, ERBB2-negative breast cancer, 1 (2.7%) tested positive for a BRCA1 GPV, and none were positive for BRCA2. Thus, in the overall cohort of 729 patients, 13 (1.8% of total cohort) had a confirmed GPV in BRCA1/2 and were eligible for PARP inhibitors. The gene discussed is ESR1; the disease is breast cancer.