ERBB2 and breast cancer: In recent years, both use of NACT and NET have increased in clinical practice.3,4 Pathological complete response (pCR), referring to the absence of invasive tumor in the breast and/or axillary lymph nodes based on the histopathologic examination (i.e., ypT0/Tis ypN0),5 is a common endpoint in studies of triple-negative and HER2-positive breast cancer.