Although pCR after neoadjuvant therapy is an important predictor of long-term prognosis and is used as the primary endpoint of many neoadjuvant studies, the relation between pCR achievement and prognosis after neoadjuvant chemotherapy may vary depending on cancer subtype; for example, pCR appears to be a suitable surrogate endpoint for patients with hormone receptor (HR)-negative and HER2 + disease but not for those with HR-positive and HER2 + disease [9]. Here, ERBB2 is linked to cancer.