The metastasis-related gene MMP11 and proliferation-related genes BIRC5, MYBL2, MKI67 (Ki67), AURKA (STK15), CCNB1, and ERBB2 (HER2) from the Oncotype DX gene set exhibit significant up-regulation in tumor samples of breast cancer (BRCA). Here, ERBB2 is linked to breast cancer.