ESR1 and breast cancer: Yeong et al. (2018) conducted histological classification and staging of 71 patients with invasive breast cancer and evaluated the vascular metastasis, lymph node metastasis, inflammatory changes in breast cancer tissue, lymph node infiltration, ER expression of estrogen receptor, p53 mutation, HER-2 expression, Ki-67 hyperplasia index, and ability of in situ recurrence and metastasis in tissue samples of patients.