Briefly, the established HER IHC interpretation categories are as follows: HER2 (0) (no membrane staining or membrane staining that is incomplete and faint/barely perceptible and in ≤10% of tumor cells) and HER2 (1+) (incomplete membrane staining that is faint/barely perceptible and in >10% of tumor cells) are categorized as HER2-negative tumors. This evidence concerns the gene ERBB2 and neoplasm.