We investigated the effect of low DAB2IP on the gene expression profile of The Cancer Genome Atlas (TCGA) patients with breast cancer, identifying genes upregulated in Luminal A tumors with low DAB2IP expression, which include genes associated with proliferation, epithelial-mesenchymal transition (EMT), and metastasis that are also enriched in Luminal B and HER2-enriched cancers, irrespective of their DAB2IP status. This evidence concerns the gene ERBB2 and cancer.