The luminal A and B cell lines are distinguished from each other, and the HER2-positive line is identified as a single subtype, while triple-negative breast cancer (TNBC) is due to the absence of estrogen receptor (ER), progesterone receptor (PR) and human epidermal growth factor receptor 2 (HER2)(3). The gene discussed is ERBB2; the disease is triple-negative breast carcinoma.