First, the application of cell lines and tumor models is singular, focusing only on breast cancer MCF-7 cells and nude mouse subcutaneous xenograft models, without covering other tumor types with high NCL expression (such as glioma and leukemia), models of different pathological subtypes or drug-resistant phenotypes, nor verifying with orthotopic and metastatic tumor models. The gene discussed is NUCLEOLIN; the disease is metastatic neoplasm.