BRCA1 and breast cancer: In contrast, a similar study of 221 Korean familial breast cancer patients [44] identified 81 deleterious mutation carriers, and demonstrated increased TN phenotype for BRCA1 mutation carriers (P <0.00001,57%, n = 35), but not BRCA2 mutation carriers (P =0.9, 13.9%, n = 36) compared with non-carriers (13%, n = 130).