CEACAM5 and lung cancer: This is exemplified by our prior findings of a 4-marker protein panel (4MP) consisting of pro-surfactant protein B (ProSFTPB), cancer antigen 125 (CA125), carcinoembryonic antigen (CEA), and cytokeratin-19 fragment (CYFRA) for personalized risk assessment of lethal lung cancer among subjects who have ever-smoked in the Prostate Lung Colorectal and Ovarian (PLCO) Cancer Screening Trial.