According to the expression of ER, PR, and HER2, breast cancer can be divided into luminal-type (ER+, PR+, HER2-), HER2 positive-type (ER-, PR-, HER2+), and triple negative breast cancer (TNBC) (ER-, PR-, HER2-) (15). The gene discussed is ERBB2; the disease is triple-negative breast carcinoma.