ERBB2 and breast cancer: Although well-documented classic diagnostic/prognostic biomarkers/profiles are reliable (for example, tumor grade and stage, p53, bcl-2, Ki-67, hormone receptor status,: human epidermal growth factor receptor 2 (HER-2) expression), there is the urgent need to differentiate between BC subclasses (for example, non-basal-like luminal A and B, basal-like, triple-negative BC)[2,3], patients with different prognoses and treatment responses to the same therapy [4-6].