IL17A and ulcerative colitis: On the other hand, Kobayashi et al. (2008) reported that the transcripts for Th17-related cytokines were more abundant in ulcerative colitis than in Crohn’s disease when the two diseases were compared and IL-23 enhanced production of IL-17 in lamina propria of patients with ulcerative colitis, while IFN-γ in patients with Crohn’s disease.