The association of IL-17 and IL-4 production has been observed in allergic disorders known to be characterized by a Th2-type response [35], but the percentage of Th17/Th2 cells in peripheral blood of healthy subjects is very low (0.04 %) and increases only slightly in the peripheral blood of allergic patients with chronic asthma (1.3 %). Here, IL17A is linked to chronic asthma.