IL4 and psoriasis: Our previous clinical studies demonstrated that TDGs were satisfactory for the treatment of mild-to-moderate psoriasis vulgaris, and the reduction of IL-2, IL-4, and IL-6, together with the secretion of neuropeptides in the peripheral blood of patients with psoriasis was observed after TDG treatment for one month; the psoriasis area and severity index (PASI) score improved by 76.65% (Fan et al., 2006a; Fan et al., 2006b).