Then, HER2 status can finally categorized as HER2 positive when the HER2/CEP17 ratio is ≥2.0 and the average HER2 gene copy number is ≥4.0 per tumor cell (group 1), HER2 status is considered as HER2 negative when the HER2/CEP17 ratio is <2.0 and the average HER2 gene copy number is <4.0 per tumor cell (group 5) by dual-probe FISH assay. The gene discussed is ERBB2; the disease is neoplasm.