Unlike other tumor markers, such as CEA, CA 15-3, CA-125, NSE, CA 19-9, CYFRA 21-1, and SCC, which are elevated respectively to the tumor growth, the use of highly sensitive CA-62 for detection early stages of lung cancer (Ia - IIb) demonstrated the ultimate diagnostic characteristics: 92.5% Sensitivity, 96.3% Specificity and 95% accuracy of LC detection at biopsy. The gene discussed is CEACAM5; the disease is lung cancer.