ERBB2 and breast carcinoma: In this study, ER (+), PR (++), and HER (−) were determined as the features of luminal A breast cancer, ER (+ − ++), PR (+), HER (+ − ++) as luminal B, ER (−/+), PR (−), and HER (+++) as HER2 overexpression in breast cancer, and ER (−), PR (−), and HER (−) as basal-like breast cancer, as shown in Fig. 1.