ROC analysis showed that serum exosomal miR‐378 and CEA were both reliable biomarkers for differentiating NSCLC from normal controls with AUC of 0.842 (Figure 2A, specificity: 81.5%, sensitivity: 77.7%) and 0.813 (Figure 2B, specificity: 80.0%, sensitivity: 73.8%), respectively. Here, CEACAM5 is linked to non-small cell lung carcinoma.