This indicator refers to the expression of 80% estrogen receptor positivity. ER refers to estrogen receptor and is one of the immunohistochemical tests for breast cancer. Positive ER indicates that endocrine therapy is possible and has a better prognosis. The higher the rate of positivity, the better the outcome. On the contrary, the prognosis is not good. In addition to the above indicators, immunohistochemical indicators of breast cancer also mainly include progesterone receptor (PR), which has the same significance as estrogen receptor. In addition, there is the epidermal growth factor receptor (EGFR) 2, a positive indicator of which represents a poor prognosis. It is recommended to consult with your doctor to determine the significance of these indicators, and to combine them with your own actual condition and other test results to make a comprehensive judgment.