In the non-pCR cohort (N=775), HER2-low cases accounted for 59.61% (n=462) of primary breast cancer, 55.36% (n=429) of residual breast cancer after neoadjuvant therapy, respectively 78.04% and 71.92% of HER2-negative primary and residual breast cancers. Here, ERBB2 is linked to breast cancer.