Membrane-anchored forms may play a role in cellular adhesion. Megakaryocyte-potentiating factor (MPF) may potentiate megakaryocyte colony formation. Interacts with MUC16. Specifically expressed in lung. Overexpressed in hereditary renal carcinoma developed by Eker rats. Proteolytically cleaved by a furin-like convertase to generate megakaryocyte-potentiating factor (MPF), and the cleaved form of mesothelin. Belongs to the mesothelin family.