TNF and chronic obstructive pulmonary disease: According to the comparison between heterozygote model (GA vs. GG, OR = 1.22, 95% CI :1.02–1.45, p = 0.03) and dominant model (GA + AA vs. GG, OR = 1.22, 95%CI: 1.01–1.48, p = 0.04), GA genotype carriers of TNF-α-308 have a higher risk of developing COPD compared to GG carriers.