The aim of this study was to explore the predictive value of carcinoembryonic antigen (CEA), squamous cell carcinoma antigen (SCCAg), and neuron‐specific enolase (NSE) in the prediction of anaplastic lymphoma kinase (ALK) mutations in advance stage non‐small cell lung cancer (NSCLC). The gene discussed is CEACAM5; the disease is lung cancer.