We demonstrate that repeated injections of IL‐23 to the ears are not able to induce IL‐23 production and a full psoriasis‐like skin phenotype, in germ‐free and RIG‐I knockout mice, and RIG‐I is also critical for a full development of skin inflammation in IMQ‐induced psoriasis‐like mouse model. This evidence concerns the gene IL23A and psoriasis.