In the neoadjuvant setting, when HER2+ BC were clasifficated by PAM50 molecular assay, HER2-E subtype was associated with a higher pCR rate (exceeding 50% in all trials) and DFS rates compared to non-HER2-E subtypes, following either trastuzumab plus chemotherapy treatment (42, 84, 85) or with dual HER2 blockade without chemotherapy. Here, ERBB2 is linked to breast cancer.