In a TNBS (2,4,6-trinitrobenzene sulphonic acid)- induced experimental colitis model in mice with genetic ablation of IL-19, Matsuo et al. found that colitis was exacerbated, with increased presence of interferon-gamma, IL-12 (p40), IL-17, IL-22, and IL-33, and decreased production of IL-4 [21]. Here, IL17A is linked to colitis.