In terms of the immunohistochemistry profile, the results were compatible in invasive lobular carcinoma (the majority being ER-positive with only a few being HER2-positive), mucinous carcinoma (the majority being both ER- and PR-positive), and tubular/cribriform carcinoma (the majority being both ER- and PR-positive with only a few being HER2-positive). This evidence concerns the gene ESR1 and invasive lobular breast carcinoma.