According to the current transcriptome based classification24,28 the following phenotypes can be discerned: normal or normal-like is the most benign phenotype that may simply reflect normal breast tissue due to a low tumor cell content in the samples; luminal A and luminal B, which are relatively benign; HER2 enriched, which is more aggressive; and basal which has the worst prognosis. Here, ERBB2 is linked to neoplasm.