Elevated IL-17 levels have been associated with the development of chronic inflammatory immune-mediated diseases [5,6,7] and several therapeutic strategies targeting IL-17 are approved for the treatment of psoriasis, psoriatic arthritis (PsA) and ankylosing spondylitis (AS) [8], pointing to the role of this cytokine in the pathogenesis of these autoimmune diseases [9,10,11]. The gene discussed is IL17A; the disease is psoriatic arthritis.