Currently, biomarkers are genetic, epigenetic, proteinic, or cellular alterations that are inherent to cancer cells, and have been an integral part of individualized cancer care.Glycoproteins, such as carcinoembryonic antigen (CEA) and cancer antigen 19-9 (CA19-9), are classical proteinic biomarkers for disease monitoring [2,3,4]. The gene discussed is CEACAM5; the disease is cancer.