ERBB2 and triple-negative breast carcinoma: Breast cancer, which is the most common cancer in women worldwide, is a heterogeneous disease that is currently classified into four major molecular subtypes, namely luminal A, luminal B, human epidermal growth factor receptor 2 (HER2), and triple-negative breast cancer (TNBC), based on the expression of hormone receptors and HER2 [1–3].