A classic example of the distinction between a vaccine’s potential efficacy and a poor clinical trial design is evidenced by an ill-conceived corporate trial in which tricom-based vaccines [carcinoembryonic antigen (cea)–Muc1–tricom, called Panvac-VF (Therion Biologics, Cambridge, MA, U.S.A.)] were administered to patients with metastatic pancreatic cancer who had already failed prior gemcitabine therapy 37. This evidence concerns the gene CEACAM5 and pancreatic neoplasm.