HLA-DRB1 and psoriasis: The haplotype HLA-A*33-B*44-C*14:01-DRB1*13-DQA1*01-DQB1*06-DPB1*04:01 was identified as a protective haplotype for psoriasis, whereas the extended haplotype HLA-A1-B37-Cw0602-DRB1*10-DQA1*01-DQB1*05 was found to be a high-risk factor for psoriasis in Koreans.37