ERBB2 and breast cancer: The molecular subtypes of breast cancer, categorized on the basis of distinct genetic characteristics, include: luminal (hormone receptors for estrogen and progesterone positive), HER-2 enriched (human epidermal growth factor receptor 2 - HER2) and basal (negative for estrogen, progesterone and HER2 receptors), also known as triple negatives (TNs)(4).