In order to magnify the CEA-mediated tumor-specific immune activities, co-administration of CEA with other immune-response enhancers such as granulocyte-macrophage colony-stimulating factor (GM-CSF) [4] or interleukin (IL)-12 [5] has yielded promising results with regards to the activation of cellular and humoral CEA-specific immune responses. This evidence concerns the gene CEACAM5 and neoplasm.