Our recent study analyzed 314 HER2 negative breast cancer patients who received NAC and found that with the pCR defined as ypT0ypN0, the pCR rate in HER2-low breast cancer was significantly lower than HER2-zero breast cancer in entire cohort(24.3% vs. 36.4%, P=0.032) and HR-positive subgroup(18.7% vs. 32.1%, P=0.035). This evidence concerns the gene ERBB2 and breast cancer.