In addition to traditional treatment modalities, the latest international treatment modality is biological therapy targeting the HER2/neu gene (i.e., c-erbB2 gene) locus. 20% to 30% of breast cancer patients have overexpression of the HER2/neu gene, and these tumors are more invasive, less sensitive to chemotherapy and more likely to metastasize. A new FDA-approved drug, Herceptin, the first human anti-HER2/neu monoclonal antibody in clinical use, has been introduced in the United States. Clinical studies have shown that it effectively inhibits the proliferation of HER2/neu-overexpressing breast cancer cells in vivo, thereby prolonging the survival of HER2/neu-positive breast cancer patients. Weekly injections of monoclonal antibodies against extracellular HER2/neu proteins are effective in 13% of HER2/neu overexpressed breast cancers. The overall effectiveness was increased to 25% when the HER2/neu antibody and cisplatin were given together, and some of the efficacy would be maintained for more than a year. burris summarized the effectiveness of Herceptin in combination with Docetaxel, with an overall effectiveness of 85.7%. The advent of new treatment modalities with HER2/neu monoclonal antibodies brings hope to breast cancer patients, but also places serious demands on pathologists. The treatment is expensive and pathologists should provide as accurate a HER2/neu gene status as possible to guide the choice of the best treatment option. Commonly used HER2/neu gene testing methods include immunohistochemistry, fluorescence in situ hybridization (FISH), and enzyme-linked immunosorbent assay (ELISA). FISH can directly and accurately determine the presence or absence of HER2/neu gene amplification, but is more expensive and cumbersome. Immunohistochemistry has become the most routine test because of its simplicity, rapidity, and economy, but there are many issues that should be noted: firstly, there are different criteria for judging immunohistochemistry, making the results of HER2/neu gene protein expression detection inconsistent, and there is no There is no consistent conclusion. Secondly, paraffin embedding and formaldehyde fixation may have an impact on the immunohistochemical results, resulting in false negatives. Thirdly, the test results are not exactly the same when different companies’ HER2/neu antibodies are used. Therefore, to make an accurate HER2/neu gene status determination, the above issues must first be unified. herceptin treatment has some cardiotoxicity and, as far as the current status of research in China is concerned, it is more consuming in terms of human, material and financial resources to carry out this treatment, and further research is needed. With the development of the economy, I have reason to believe that gradually more breast cancer patients in the more economically developed areas of China will be able to benefit more from Herceptin.