Finally, the standard tumor markers, such as carcinoembryonic antigen (CEA), carbohydrate antigen 19-9 (CA 19-9), and CA 72-4, have shown little benefit as a method for screening.4 Therefore, there is a need for highly sensitive and specific biomarkers with efficient detection techniques to allow widespread screening of patients for early detection of GC. The gene discussed is CEACAM5; the disease is gastric cancer.