MSLN and mesothelioma: However, MSLN is expressed at a high level in almost all mesothelioma and many solid tumors such as in lung cancer (60–70%), pancreatic cancer (80–85%), cholangiocarcinoma (60–65%), ovarian cancer (60–65%), gastric cancer (50–55%), colon cancer (40–45%), breast cancer (25–30%), and endometrial cancer (20–25%) [7].