Classifying this data set by intrinsic breast cancer subtypes based on Hu et al. [26] we furthermore revealed a pronounced downregulation of ITIH5 mRNA in luminal B (median FC: 31.4-fold downregulation), HER2-enriched (median FC: 22.1-fold downregulation) and basal-like breast cancer (median FC: 25.7-fold downregulation) (Fig. 1b), i.e. breast cancer subtypes known to be associated with high risk for metastasis. Here, ERBB2 is linked to breast cancer.