CD8A and psoriasis: Markers tagging HLA-Cw∗0602 generate the strongest effects, which is in line with previous reports.17,21,24,44,61 CD8+ T cells are increased in the epidermis of lesional psoriatic skin, and the association of psoriasis susceptibility primarily with class I HLA alleles might reflect the critical role of psoriasis-associated (auto-)antigen presentation to pathogenic CD8+ T cells.62