Membrane-anchored forms may play a role in cellular adhesion. Megakaryocyte-potentiating factor (MPF) potentiates megakaryocyte colony formation in vitro. Interacts with MUC16. Expressed in lung. Expressed at low levels in heart, placenta and kidney. Expressed in mesothelial cells. Highly expressed in mesotheliomas, ovarian cancers, and some squamous cell carcinomas (at protein level). Both MPF and the cleaved form of mesothelin are N-glycosylated. Proteolytically cleaved by a furin-like convertase to generate megakaryocyte-potentiating factor (MPF), and the cleaved form of mesothelin. Antibodies against MSLN are detected in patients with mesothelioma and ovarian cancer. Minor form. Major form. Soluble form found in the sera from patients with ovarian carcinoma. Belongs to the mesothelin family.