CEACAM5 and non-small cell lung carcinoma: These findings imply that circ_0008103 and circ_0061407 present in serum exosomes were closely linked to NSCLC, and had correlations with the aggressive characteristics (distant metastasis, advanced tumour stages) of NSCLC, showing superior diagnostic power to discriminate M0 and M1, stages I-II and III-IV subpopulations than CEA, NSE, and CYFRA21-1.