Neoadjuvant chemotherapy (NAC) is currently administered to patients with locally advanced breast cancers (BC), to BC of poor prognosis (triple-negative and HER2-positive tumours, or BC with nodal involvement and/or high proliferation rates), or to early stage BC having an indication of systemic therapy.1,2 Beyond increasing breast-conserving surgery rates,3–5 NAC enables the evaluation of systemic treatments in vivo, thus making it theoretically possible to discontinue ineffective treatments.6,7 Response to NAC also carries important prognostic information. Here, ERBB2 is linked to neoplasm.