TNF and asthma: A further evaluation of the genotype distribution of these polymorphisms showed that carriers of the AA genotype of LTA4H A-9188>G or IL-4Rα A1727>G polymorphisms and carriers of the GG genotype of TNFα G-308>A polymorphism were at an increased risk of having difficult asthma when compared with carriers of other genotypes of these polymorphisms (OR = 3.0; 95%CI = 1.6–5.7; p = 0.001, OR = 2.4; 95%CI = 1.3–4.6; p = 0.006 and OR = 2.2; 95%CI = 1.1–4.1; p = 0.019, respectively).