Thus, the precise grouping of breast cancers into clinically relevant subtypes is of particular importance for therapeutic decision-making.4After studying several gene expression panels, five intrinsic breast carcinoma subtypes were identified that correlate with the prognosis: Luminal A, Luminal B Human Epidermal growth factor Receptor-type 2 (HER-2) negative, Luminal B HER-2 positive, HER2-enriched and triple-negative. Here, ERBB2 is linked to breast carcinoma.