Genetic testing for breast cancer is very meaningful, and it is recommended that every breast cancer patient should undergo genetic testing if conditions permit, to understand the situation of breast cancer gene expression has multiple meanings, as follows: 1) Determining hereditary genes: to understand whether there are genes that are hereditary for breast cancer, such as BRCA1 and BRCA2. 2) Judging the severity: it can determine the degree of differentiation and grading of breast cancer. 3) Prognosis: It can be used to determine the prognosis of breast cancer, to understand the cure rate, recurrence rate, mortality rate, etc. 4) Guidance on medication: For example, Herceptin, a treatment drug for Her-2 gene expression, has changed the traditional mode of breast cancer medication, making early breast cancer have a chance of cure and reducing the risk of breast cancer recurrence by about 50%. . Therefore, genetic testing for breast cancer is very meaningful and can help breast cancer patients to develop more accurate and appropriate treatment plans, thus improving the effectiveness of treatment.