IL20 and psoriasis: While we have observed attenuated development of skin lesions in CD11c-IL-17Aind/ind mice after radon exposures, the gene expression of soluble inflammatory or differentiation factors produced by immune cells or keratinocytes that are related to the chronic state of psoriasis was either not affected or significantly increased as in the case of Il20 at the early time point or of Il1f9 and Defb3 at the late time point (35, 36).