We found that the association of DQA1*02:01, DQB1*03:03, and DRB1*07:01 with psoriasis was nearly completely due to the effects of C*06:02 or B*57:01, since conditioning DQA1*0201 and DRB1*0701 on C*06:02 resulted in p = 0.017, OR = 1.21 and p = 0.199, OR = 1.11, respectively; and conditioning DQB1*0303 on B*57:01 resulted in p = 0.038, OR = 1.33. Here, HLA-DRB1 is linked to psoriasis.