The expression of CEA is increased during the occurrence and development of lung cancer [146], and it has also become a valuable tumour marker for monitoring the treatment response, providing a basis for establishing phase I clinical trials that can evaluate the efficacy and safety of CEA-targeted CAR-T cells in the treatment of lung cancer (NCT02349724 and NCT04348643). The gene discussed is CEACAM5; the disease is lung carcinoma.