The breast is the target organ of female endocrine secretion. Under the action of female sex hormones (estrogen and progesterone), the breast completes the process of development to lactation. Female hormones, especially estrogen, also play an important role in the development of breast cancer, and for estrogen to work it needs to bind to a special structure on the cell surface, the hormone receptor. ER and PR represent estrogen receptors and progesterone receptors, respectively. The ER and PR of breast cancer cells can help determine whether the tumor is sensitive to endocrine therapy; breast cancers with positive ER and PR have up to 70% sensitivity to endocrine therapy; while breast cancers with negative ER and PR have less than 10% sensitivity to endocrine therapy. In other words, the status of ER and PR is an indicator to decide whether a breast cancer patient can undergo endocrine therapy or not. Breast cancer Her-2 is a member of the epidermal growth factor receptor family, a family that plays an important role in cell signaling and is a key regulator of cell growth, differentiation and survival. Normally, Her-2 is expressed only during fetal life and by adulthood, it is only lowly expressed in very few tissues. The oncogene of Her-2 plays a major role in the pathogenesis of breast cancer, and overexpression of Her-2 is indicative of poor prognosis in breast cancer. Overexpression of the HER2 gene is present in nearly one-third of breast cancer patients, and amplification of this gene is now an important indicator in clinical medicine for assessing the malignancy of breast cancer and the risk of postoperative recurrence and prognosis in breast cancer patients.