ERBB2 and neoplasm: Among tumours with ER, PR and HER2 data, 96.7 % were ER+, 86.8 % were PR+ and 83.4 % were HER2− in BRCA2 mutation carriers, vs. 90.3 % ER+, 78.6 % PR+ and 89.5 % HER2− in BRCA1 mutation carriers.