In addition to classical HLA genes such as HLA-C, HLA-B and HLA-DQA2, we also find association of non-HLA genes in the MHC region such as POU5F1, NFKBIL1, NOTCH4, MICA, IER3 and OR12D2 with psoriasis. This evidence concerns the gene HLA-DQA2 and psoriasis.