ERBB2 and breast cancer: Regarding the impact of HER2-enriched subtype, further research is strongly needed in light of our results as well as limited, if any, benefit from anti-HER2 treatment in the neoadjuvant–adjuvant settings in patients with high ESR and low HER2 expression [4,6,10,11], particularly in molecularly heterogeneous HER2-positive/HR-positive breast cancer.