IL20 and psoriasis: Although a preclinical study in mice transplanted with human psoriatic plaques or nonlesional psoriatic skin plus activated peripheral blood mononuclear cells showed improvement in the semiquantitative clinical psoriasis scores following treatment with an anti‒IL-20 antibody, suggesting that targeting IL-20 may improve PsO symptoms in humans [24], this response is not necessarily predictive of efficacy in humans with PsO because there is no animal model specific to PsO [31].