By using the SpA model, van Tok et al. (20) reported that treatment with anti-IL-23R before the signs of arthritis/spondylitis onset could completely inhibit the development of spondylitis and peripheral arthritis, whereas treatment with anti-IL-23R 1 week after 50% arthritis incidence failed to reduce the incidence and the severity of experimental SpA. The gene discussed is IL23R; the disease is spondylitis.