observed an increased proportion of Th2, Th17, IL-18+, IL-18+ Th2 and IL-18+ Th17 cells in blood CD4+ T cells of asthma patients, and found that Th2 cells responded to allergen stimulation by expressing excessive IL-18 and IL-18Rα in an ova-induced mouse model of asthma (100). This evidence concerns the gene CD4 and asthma.