Invasive ductal breast carcinoma (IDC) is divided into biologically distinct and clinically relevant subgroups on the basis of immunohistochemical status of the estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor 2 (HER2) and Ki-67 proliferation index [1, 2]. Here, ERBB2 is linked to invasive ductal breast carcinoma.