Tumorigenesis involves alterations in a variety of genes and their products. Gene amplification leads to an increase in MRNA transcription and overexpression of the corresponding proteins, and the detection of such gene amplification is important for tumor diagnosis, prognosis, selection of treatment options and prediction of the final outcome of the tumor. HER-2/neu oncogene belongs to the EGF receptor family and is a proto-oncogene, which starts to be expressed mainly at embryogenesis. In adulthood, a small amount of HER-2/neu protein can be detected in epithelial cells of normal tissues by immunohistochemical methods, but there is no gene amplification. The HER-2/neu proteins are involved in the regulation of cell growth, reproduction and division, as well as the control of tumor growth and other complex regulatory functions. HER-2/neu gene amplification is associated with recurrence, metastasis and poor prognosis of breast cancer, that is to say; for breast cancer patients, regardless of whether the lymph nodes in the surgical specimen are negative or positive, as long as there is HER-2/neu gene amplification or overexpression. gene bracketing or overexpression, it confirms that the proliferation of this tumor cell is accelerated and prone to early metastasis and recurrence, hence short survival and poor prognosis. The detection of HER-2/neu gene overexpression is usually divided into two categories: 1) protein level detection; immunohistochemistry (IHC), Western Blot, ELISA. 2) gene amplification detection: Fish, Southern. Currently, both of these tests have been used in our department, which can provide convenient services for the diagnosis and treatment of these patients. In clinical breast cancer treatment, patients with HER-2/neu amplification will develop drug resistance to certain drugs, such as 5-fluorouracil and tribenoxolone. In recent years, the FDA has approved a new drug, Herceptin, which is an immunotherapeutic drug that specifically inhibits the growth of cancer cells with HER-2/neu oncogene amplification, resulting in a much improved prognosis, especially for patients who develop resistance to certain drugs. At the same time, a variety of prosecutions such as follicular lymphoma, set cell lymphoma, and large B-cell lymphoma in lymphoma have been carried out, providing a great convenience for gene therapy of such lesions.