IL23R and ankylosing spondylitis: Since the first identification of IL23R as susceptibility gene in IBD by Duerr et al.[3], various GWAS and cohort studies have confirmed IL23R not only as a major susceptibility gene in IBD but also in the pathogenesis of other autoimmune diseases such as psoriasis [26], [27] and ankylosing spondylitis [28], implicating common proinflammatory pathways.