Alternatively, tumor antigens expressed during fetal development or at immune-privileged sites [83], e.g., CEA (carcinoembryonic antigen), are present in certain cancers, such as colorectal carcinoma, pancreatic adenocarcinoma, and breast cancer [84], and have been considered for their use in immunotherapies. The gene discussed is CEACAM5; the disease is pancreatic adenocarcinoma.