Similarly, IL‐22 is highly expressed in skin lesions of patients with psoriasis, and IL‐22 levels found in serum were correlated with disease activity.95, 96 Furthermore, experimental psoriasis was significantly ameliorated in IL‐22 KO mice or following neutralisation of IL‐22 via anti‐IL‐22 in WT mice.97 This evidence concerns the gene IL22 and psoriasis.