Serum carcinoembryonic antigen (CEA), cancer antigen 125 (CA125), cytokeratin 19 fragment (CYFRA21-1), and squamous-cell carcinoma-related antigen (SCC-Ag) might be relevant for the prognosis of patients and have been widely used as biomarkers predicting the efficacy of chemotherapy or targeted therapy in NSCLC patients (20–27). This evidence concerns the gene KRT19 and non-small cell lung carcinoma.