Carcinoembryonic Antigen-Related Cell Adhesion Molecule 7 (CEACAM7) is a member of the immunoglobulin superfamily A and CEA family. CEACAM7 localizes to the cell membrane and contains one Ig-like C2-type domain and one Ig-like V-type domain. The expression of CEACAM7 is significantly decreased in rectal cancer. Differences in CEACAM7 expression levels between long-term survivors and those with recurrent disease introduce a potential tumor marker to define a subset of patients who benefit most from adjuvant therapy.