Carcinoembryonic antigen cell adhesion molecule 5 (CEACAM5), also known as CEA or CD66e, is a highly glycosylated cell surface protein anchored in the membrane via a glycosylphosphatidylinositol (GPI) anchor and normally functions as an adhesion molecule that can interact with CEACAM6 and CEACAM1 and plays a pivotal role in cancer biology [21,22]. This evidence concerns the gene CEACAM5 and cancer.