Effects of depletion of Tregs by anti-CD25 administration, and of administration of anti-IFN-γ, anti-IL-17A or anti-IL-17F on fibrosis after three cycles of DSS, were evaluated first by quantification of collagen deposition in mucosa and submucosa by MSB trichrome staining (Fig. 6a–c). Here, IL17A is linked to fibrosis.