Despite the fact that cytokines have traditionally been thought of as cancer biomarkers, a few other glycoproteins, most commonly CEA and tissue inhibitor of metalloproteinase 1 (TIMP1), are involved in cellular adhesion that is frequently produced in gastrointestinal tissue and their abnormal levels have been found in serum of lung, colorectal and breast cancer [22]. The gene discussed is CEACAM5; the disease is breast cancer.