MSLN and neoplasm: Mesothelin (MSLN), a cell surface glycoprotein, is generally expressed in mesothelial cells lining the pleura, peritoneum (minimally on the epithelial cells of the ovaries and fallopian tubes) and pericardium, however highly expressed in many tumour cells, including OC; its soluble form can also be found in the bloodstream of OC patients [90].