IL17A and ulcerative colitis: Moreover, increased P3 iMPs or P2 DCs in vivo in mice with local or severe colitis, respectively, and their IL-17 production ex vivo, suggests a role for IL-17 in spontaneous colitis in Muc2-deficient mice, particularly group B mice with extensively spread colitis, and mimics the situation in human ulcerative colitis[37,38].