The addition of pertuzumab, a monoclonal antibody that inhibits HER2-HER3 dimerization and activates antibody-dependent cellular cytotoxicity (ADCC), to neoadjuvant treatment with chemotherapy and trastuzumab has significantly improved pathological complete response (pCR) rates in patients with HER2-positive breast cancer [1–3]. Here, ERBB2 is linked to breast cancer.