Finally, the histological diagnosis of peritoneal mesothelioma was performed on the basis of a positive staining for keratin markers such as calretinin and thrombomodulin, as well as negative staining using markers for adenocarcinoma such as carcinoembrionic antigen (CEA), CA-125 and CK 5/6. The gene discussed is CALB2; the disease is adenocarcinoma.