The expression level of DDB2, RPA3,RAD50, RRM2B, and UBE2A was higher in breast cancer tissues with lymph node metastasis compared with breast cancer tissues without lymph node metastasis, which was estimated by the distribution of their expression level between N0 and N1–N3 stages. Here, RAD50 is linked to metastatic malignant neoplasm in the lymph nodes.