In conclusion, our study showed an elevated expression of IL-22 by stimulated PBMCs and CD4+T cells, increased frequencies of IL-22-producing CD4+T cells in BD patients with active uveitis, and an increased expression of IL-22 mRNA in erythema nodosum skin lesions of BD patients and point to a possible role of this lymphokine in the pathogenesis of this disease. The gene discussed is CD4; the disease is Behcet disease.