CEACAM5 and gastric cancer: A combination of serum CEA and CA19–9 has been indicated to obtain higher specificity than serum CEA alone[10]; the combination of CEA, CA125, and CA19–9 has been reported to attain higher sensitivity than CEA alone.[11] What is more, the combination CEA and LncRNA was more accurate [12] and the combination of CEA and PG was proved to improve sensitivity.[13] Recent studies [14–16] showed that DNA methylation was a novel biomarker for diagnosis of early gastric cancer and the combination of CEA and DNA methylation might be more efficient.