We found that the levels of IL-6, IL-8, TNF-α, and IFN-γ in the smoker and COPD III-IV groups were significant higher than those in the non-smoker and COPD I-II groups, and TLR2 in mononuclear cells of the peripheral blood was significantly correlated with the clinical classification of the patients (Figs. 3A–3E). This evidence concerns the gene IFNG and chronic obstructive pulmonary disease.