Acer3−/− mice that survived DSS treatment showed more severe colitis, as evidenced by a greater colon shortening (Figure 8a), higher levels of inflammatory cytokines (Il-1β, Il-6, Il-23a and Tnf-α) (Figure 8b), higher MPO activity (Figure 8c) and more severe pathological manifestations (Figures 8d and e). The gene discussed is IL23A; the disease is colitis.