MAF and colitis: Interestingly, also IL-10-deficient mice developed intestinal inflammation with delayed onset and less severity in 5- to 6-month-old animals when maintained under SPF conditions.18 In addition, Hh-free transgenic mice with Treg-specific c-Maf deficiency developed mild spontaneous colitis at a later age of 6 to 12 months.57 The protection from early disease onset in Hh-free DC-LMP1/CD40 mice suggests that Hh might be a very potent disease driver.