Literature on the role of serum tumor biomarkers for lung cancer diagnosis is scarce, and, so far, none is recommended for this purpose [13,15]. Carcinoembryonic antigen (CEA), CYFRA 21-1, and NSE seem to be useful in the presence of suspicious lung findings or for early detection of lung cancer in patients at risk, in association with low-dose chest CT scans [4,15,16]. Here, ENO2 is linked to lung cancer.