We grouped the tumors into 3 subtypes based on expression of either the hormone receptors (HR) or human epidermal growth factor receptor 2 (HER2) (7): those that were HER2+ regardless of the HR status, those that were negative for all hormone receptors (triple negative breast cancer; TNBC) and those that were HR+ and HER2-. Here, ERBB2 is linked to triple-negative breast carcinoma.