BRCA1 and breast cancer: Finally, a cohort of 64 Ashkenazi Jewish TNBC patients unselected for age of onset and familial aggregation of breast cancer was screened for mutations in BRCA1 and BRCA2. In all Ashkenazi Jewish breast cancer cases, approximately 10% of patients carry one of three different founder mutations in BRCA1 and BRCA2. In the investigated Ashkenazi Jewish TNBC cohort (n = 64), 19 BRCA1 (29.7%) and 6 BRCA2 (9.4%) mutations could be detected when screening for the three founder mutations [5].