ERBB2 and neoplasm: It is noteworthy that most disagreements (68.8%) between pathologists’ scores were observed within the HER2-low range (later consented as IHC score 0 or 1 +), especially near the cut-off for HER2 ultra-low category exhibiting a HER2 score of 0 with incomplete and faint staining in ≤ 10% of tumor cells.