ERBB2 and breast cancer: In fact, on one hand, with the emergence of novel treatment strategies directed to patients with HER2-low-positive breast cancer, a stricter adherence to FDA/ASCO-CAP rules for HER2 scoring would be advisable, especially in the light of the suboptimal inter-pathologist agreement rates recently reported with regards to the distinction between IHC scores 0 and 1+5.