Nevertheless, the current tumor markers, such as carcinoembryonic antigen (CEA), cytokeratin 19 fragment (CYFRA 21–1), carbohydrate antigen 19-9 (CA19-9), and neuron-specific enolase (NSE), meet a different degree of detection sensitivity or specificity problems for LUAD diagnosis (5, 6). This evidence concerns the gene CEACAM5 and neoplasm.