Recently, a genome-wide scan study in 1,409 psoriasis cases and 1,436 controls revealed associations between three genes of the IL-23 pathway (IL23A, IL23R and IL12B), two genes of nuclear factor-κB (NF-κB) pathway (TNIP1 and TNFAIP3) and psoriasis [5]. Here, IL23A is linked to psoriasis.