Specifically, we compared gene expression in (1) TNBC tumor tissues to normal tissues [22], (2) TNBC tumors to non-TNBC tumors (Bittner et al. International Genomics Consortium (IGC) 2005), and (3) TNBC tumors to ER-negative/HER2-positive tumors [26]. The gene discussed is ESR1; the disease is neoplasm.