On the same path, results obtained during the last years suggested an analogue potential for IL-31, not only due to its role in the pathogenesis of some diseases (AD, prurigo, chronic urticaria, psoriasis, vasculitis, connective tissue diseases, asthma) but also because of the hypothesis speculated by Wong [26] firstly and then extended by our group [16, 18, 37, 48]. This evidence concerns the gene IL31 and psoriasis.