IL23A and Crohn disease: Ustekinumab, a human IL-12 and IL-23 antagonist that binds to their p40 subunit so that they subsequently cannot bind to their receptors to trigger pro-inflammatory cytokine release, is currently approved for use in moderate-severe PsO, PsA and Crohn’s disease, while its efficacy in the treatment of axSpA was not demonstrated in 3 placebo-controlled trials, although its safety profile was consistent with studies in other indications (31).