Calretinin, D2-40 (podoplanin), Wilms’ tumor-1 (WT1) and CK5/6 are recommended for distinguishing mesothelial differentiation, whereas the common markers of carcinoma are BerEP4, CEA (carcinoembryonic antigen), pancytokeratins and, more recently, claudin-4 as a marker of adenocarcinoma. This evidence concerns the gene CEACAM5 and adenocarcinoma.