We first determined mRNA levels of NME4 (encoding NDPK-D), CDH1, and KRT18 (encoding the two well-known epithelial markers E-cadherin and cytokeratin 18, respectively), in an important cohort of 526 human breast tumors from patients with well-documented follow-up by using RT-qPCR (Additional file 20: Table S3). This evidence concerns the gene KRT18 and breast neoplasm.