Currently used for clinical screening of lung adenocarcinoma tumor markers with carcinoembryonic antigen (CEA), cytokeratin-19 fragment (CYFRA21-1) and neuron-specific enolase (NSE) and so on, but these protein markers are prone to false positive, and their specificity and sensitivity are not high (Yuan et al., 2022). This evidence concerns the gene CEACAM5 and neoplasm.