CLDN4 and breast carcinoma: For example, the upregulation of keratins (KRT7, KRT8, KRT18 and KRT19) and LMNA genes highlighted the expected similarities between mesothelial cells and breast carcinoma cells,29 while other genes central to mesothelial (WT1, MSLN, DES and CDH2) or epithelial (CDH1, CLDN4 and CLDN7) cell identity confirm their differences.