It has been proposed that serum CLP in combination with a panel of other biomarkers, including sCD26, matrix metalloproteinases (MMPs)-1, -7, -9, epidermal growth factor (EGF), cytokeratin 19 fragment (CYFRA 21.1), and carcinoembryonic antigen, can identify with high sensitivity stage I NSCLC (94.7%) and 100% small-cell lung cancers [159]. The gene discussed is EGF; the disease is small cell lung carcinoma.