Breast cancer can be divided into subtypes according to histopathological features such as progesterone receptor (PR), estrogen receptor (ER), or erb-b2 receptor tyrosine kinase 2 (ERBB2 or HER2) status, and include ER-positive, HER2-positive, or triple-negative breast cancer [2]. The gene discussed is ESR1; the disease is triple-negative breast carcinoma.