Because of the similar lung mass or nodules in pulmonary images between lung TB and lung cancer, some patients were examined plasma cancerous indices such alpha-fetoprotein (AFP), CA199, carcino embryonic antigen (CEA), and inflammatory indices such as lactate dehydrogenase (LDH), C-reactive protein (CRP), adenosine deaminase (ADA) for differential diagnosis. This evidence concerns the gene AFP and lung cancer.