ERBB2 and breast cancer: Studies have also shown differing rates of response by ERBB2 status, with lower rates of pCR consistently seen with ERBB2-low BC, although rates by HR status have been conflicting.5,6,7,8,10,11,20,21,22 The extent to which low ERBB2 expression contributes to the observed disparities in clinical outcomes among patients with TNBC by race and ethnicity is currently unknown.