Mesothelin is a promising target for CAR T cell therapy (16–18), because up to 30% of cancers are detected with high levels of mesothelin expression, such as epithelial mesothelioma, pancreatic cancer, ovarian cancer, squamous cell carcinomas, adenocarcinomas and triple negative breast cancer (19–21). The gene discussed is MSLN; the disease is malignant epithelioid mesothelioma.