MSLN and pancreatic ductal adenocarcinoma: An ideal CAR T cell target for the treatment of pancreatic ductal adenocarcinomas is mesothelin, a glycoprotein highly expressed by pancreatic ductal adenocarcinomas, ovarian cancers, and malignant pleural mesothelioma, with low levels of expression on mesothelial cells in the peritoneum, pleura, and pericardium [106].