CEACAM5 and neoplasm: Additionally, lower levels of exosomal circ_0061407 and circ_0008103 were closely correlated with more aggressive features (distant metastasis or advanced tumour stages) of NSCLC, showing superior diagnostic sensitivity and specificity than traditional tumour markers (CEA, NSE, and CYFRA21-1) to discriminate M0 and M1, tumour stages I-II and III-IV subpopulations (Fig. 6).