In addition to the traditional Tumor-Node-Metastasis (TNM) staging system, the treatment strategy of breast cancer is more dependent on its molecular typing characteristics, such as estrogen receptor (ER), progesterone receptor (PR), HER2, Ki67, and other risk factors like genomic markers (eg, BRCA1, BRCA2, and PIK3CA), and immunomarkers (eg, PD-L1) (2, 3). This evidence concerns the gene ESR1 and breast cancer.