IL17A and psoriasis: HLA-Cw*0602 is a psoriasis risk allele. rs2524094 associated with allele-specific expression of HLA-C. A allele is displayed in HLA-C*0602 which results in lower promoter activity at enhancer κB element, and thus, responds weakly to TNF-a, IL-17 and IL-22 stimulationHLA-Cw*0602 also contains a 3bp deletion (rs10657191) in the interferon response stimulated element (ISRE) resulting in the non-responsiveness to IFNs.