Hence, in this study, miR-620 was selected for large-scale verification in the serum exosomes of NSCLC patients and healthy donors, establishing a diagnostic group that binds to cytokeratin 19 fragment (CYFRA21-1) and carcinoembryonic antigen (CEA) for the first time to achieve ideal diagnosis of NSCLC with high sensitivity and specificity. The gene discussed is KRT19; the disease is non-small cell lung carcinoma.