ERBB2 and neoplasm: In that study, the distribution of HER2 IHC score (0/1+, 2+ or 3+) in tumours with HER2 copy number <4.0 and those with ≥4.0–6.0 was similar whereas the difference in the distribution was significantly different between ratios <2 and ≥2.0 with 47% of cases with a ratio ≥2.0 scored as 3+.20 Although 50% of cases with HER2 copy number ≥6.0 scored 3+ this was observed only when the ratio was ≥2.0 compared to 11% when the ratio was <2.0; further emphasising the impact of the HER2/CEP17 ratios on HER2 protein expression.20