Carcinoembryonic antigen (CEA) and cytokeratin-19 fragments (CYFRA 21-1) are widely used in certain regions of the world, such as Eastern Asia (Zhi et al, 2015), for differential diagnosis in NSCLC (Schalhorn et al, 2001; Molina et al, 2003, 2010, 2016) and have demonstrated great potential for predicting early response to chemotherapy (Vollmer et al, 2003; Holdenrieder et al, 2004, 2006). The gene discussed is KRT19; the disease is non-small cell lung carcinoma.