Besides that, carcinoembryonic antigen (CEA), squamous cell carcinoma antigen (SCC) and neuron-specific enolase (NSE) are common biomarkers that are used to diagnose lung cancer and make and prognostic predictions, but the differences in biomarker levels among lung cancer patients stratified by age have not yet been reported25,26. Here, CEACAM5 is linked to lung cancer.