The prime suspect behind inflammatory bowel disease (IBD) has been wrongly accused. Work by Hue et al. (page 2473) and Kullberg et al. (page 2485) reveals that the cytokine IL-12 was merely a cover for the real IBD culprit, IL-23. IL-23 promotes inflammation by corrupting not only adaptive immunity, as previously thought, but also the innate immune system. IL-12, an activator of adaptive immuni...