According to our study, the two statuses of HER2-low or HER2–0 did not seem to have different clinicopathological features in breast cancer, and both expression statuses had no effect on the pCR as well as DFS and OS of the patients, although in the HR- subgroup of patients, HER2–0 seemed to have a better DFS compared to the HER2-low tumors (P=0.027), taking into account the fact that in the association between pCR and survival in HR- patients, we get that this conclusion does not contradict the existing logic (32). This evidence concerns the gene ERBB2 and breast cancer.