CEACAM5 and non-small cell lung carcinoma: Diagnostic advantage was also achieved for stage I patients (for exosomal RP5-977B1, AUC = 0.8377, P < 0.001, for serum CEA, AUC = 0.5694, P = 0.3920, for serum CYFRA21-1, AUC = 0.5792, P = 0.1521), indicating that exosomal RP5-977B1 exhibited advantages in the diagnosis of early-stage NSCLC (Fig. 3C, Tables 1, 2).