IL23A and psoriasis: Functional studies investigating IL-23 contribution to the pathogenesis of psoriasis proved: (i) its ability to induce the development of psoriasiform skin lesions in mice by intradermal injection [181,182,183]; (ii) the inhibition of psoriasis development by injection of IL-23-neutralizing antibodies in two different mice models [153,182]; (iii) the absence of psoriasiform lesions after imiquimod application in IL-23p19 knockout mice in comparison to wild-type mice [62].