ERBB2 and neoplasm: Regarding the HER2-tissue based biomarkers, HER2 tumor protein abundance was the most promising for prediction of pCR, (OR 1.75; p = 0.01, c = 0.76), while HER2-enriched and HER2 3+ expression had lower concordance (c = 0.59, p = 0.2 and c = 0.56, p = 0.3, respectively) (Table 2).