ERBB2 and carcinoma: For example, LumA tumors (PR-positive/HER2-negative; PR-negative/HER2-negative) and LumB tumors (PR-negative/HER2-positive; PR-positive/HER2-positive) are ERα-positive, while the other subtypes are ERα-negative, and BRCA1-mutated carcinomas do not express ERα, but all of them can originate from various histological types3–6.