Mesothelial cells are generally positive for calretinin, thrombomodulin, cytokeratin 5/6, WT1, D2-40, vimentin, HBME-1 and CD44H, while polyclonal and monoclonal carcinoembryonic antigen, Ber-EP4, Leu-M1, CA-125, B72.3, PAX8, MOC 31, CA19-9 and ER are the most common markers of carcinoma. The gene discussed is ESR1; the disease is carcinoma.