ERBB2 and breast cancer: Some clinic-pathological features and biological indicators have been reported as prognostic factors for breast cancer patients, including hormone receptor (HR) status, which refers to estrogen receptor (ER) and progesterone receptor (PR) status, human epidermal growth factor receptor2 (HER2) status, histological grade, pathological type, TNM staging, age at diagnosis, marital status and some tumor markers such as CEA, CA15-3 (2–5).