As shown in Table 1, the clinicopathologic features of 557 breast cancer patients are summarized, including histological grade, tumor size, lymph node metastasis and the status of estrogen receptor (ER), progesterone receptor (PR), epidermal growth factor receptor 2 (C-erbB2) and tumor protein 53 (P53) which were investigated in this study. The gene discussed is ESR1; the disease is breast cancer.