Breast cancer genetic testing is suitable for patients who are uncertain about human epidermal growth factor receptor-2, in which case genetic testing is required. After breast cancer surgery, based on pathology as well as immunohistochemistry, it is concluded that the epidermal growth factor receptor is mostly likely to be (++), but (++) cannot determine whether the epidermal growth factor receptor is positive or negative, so further genetic testing is performed. The genetic testing is done by NGS, which is a second-generation sequencing method. This way, after Fish testing, it is possible to determine whether the epidermal growth factor receptor is positive or negative. If it is positive, it is suitable for targeted therapy, and if it is negative, there is no targeted therapy drug to use.