mRNA expression of SMYD3 had no statistical significance with patients’ age, age of menarche, menopausal status, tumor size, pathological type, immunohistochemical indexes, FDRs with breast cancer, and clinical staging (P>0.05), but had statistical significance with lymph node metastasis, HER2 status, subtypes of breast cancer, and metastasis situation (Table 6). Here, ERBB2 is linked to breast cancer.