Recently, we showed that the association of IL-1α, IL-17A, IL-22, OSM and TNFα exhibits a very strong synergy on keratinocytes by increasing the expression of inflammatory/innate immunity related molecules such as chemokines and antimicrobial peptides, generating an in vitro model of skin inflammation mimicking features of psoriasis [10], [11]. This evidence concerns the gene IL22 and psoriasis.