Therefore, we propose to take HER2 IHC 1+ and IHC 0 as a group, and we found that the DFS of the HER2 IHC 2+ group was significantly better than that of HER2 IHC 1 and IHC 0 group in some subgroups such as the invasive ductal carcinoma subgroup, the T1–T2 subgroup, grade 2 subgroup, and lymphovascular invasion subgroup. Here, ERBB2 is linked to invasive ductal breast carcinoma.