ERBB2 and triple-negative breast carcinoma: Triple negative breast cancer (TNBC) is a molecularly diverse breast cancer subtype which shows hormone receptor immunohistochemistry (IHC) stains of less than 1% for oestrogen and progesterone; and the absence of human epidermal growth factor receptor-2 (HER2) protein expression or HER2 gene amplification or both [1, 2].