In a study performed on 60 patients with psoriasis and 30 healthy controls, the authors found significantly higher levels of IL-6, IL-20 and IL-22 in psoriatic patients than in the control group, the concentrations of IL-20 and IL-22 being positively correlated with disease severity measured with PASI and body surface area (BSA). The gene discussed is IL22; the disease is psoriasis.