According to the LASSO method, seven features with optimal λ values, including reproductive history, lymph node metastasis, ER status, PR status, CA153, CEA and endocrine therapy, were selected for the model with only clinicopathological features (clinicopathological-feature alone model) (Figure 2A, 2B). The gene discussed is ESR1; the disease is metastatic malignant neoplasm in the lymph nodes.