Up to 50% of HER2-positive breast cancers and a subset of triple-negative breast cancers (TNBCs) achieve pathologic complete response (pCR) following neoadjuvant chemotherapy (NAC), thereby allowing NAC response to act as corollary for disease-free survival in TNBC and HER2+ breast cancer patients [70,71,72]. Here, ERBB2 is linked to triple-negative breast carcinoma.