The top 20 pathways were screened out (Figure 3), which were closely related to Tuberculosis, Toxoplasmosis, Hepatitis B, lipids and atherosclerosis, Shigellosis, MicroRNAs in cancer, Leishmaniasis, the IL-17 signaling pathway, the NF-kappa B signaling pathway, Proteoglycans in cancer, human immunodeficiency virus 1 infection, chemical carcinogenesis receptor activation, Pertussis, small-cell lung cancer, prostate cancer, Amoebiasis, the C-type lectin receptor signaling pathway, parathyroid hormone synthesis, secretion and action, the TNF signaling pathway, and Legionellosis. The gene discussed is TNF; the disease is small cell lung carcinoma.