Immunohistochemical staining using two mesothelin (5B2, and MN-1) and three MPF (MPF25, MPF44, and MPF49) antibodies were performed in 218 selected tumor tissues including ovarian serous carcinoma, pancreatic ductal carcinoma, thymic tumors, and malignant mesothelioma. The gene discussed is MSLN; the disease is neoplasm.