IL21 and inflammatory bowel disease: Additionally, identified within the human IBD ‘Immune effector module’, IL21 was over-expressed in ulcerative colitis (Fig. 7f) and showed the highest abundance in the LPLs from H. hepaticus double-deficient Prdm1fl/fMaffl/fCd4Cre-infected mice (Fig. 7g), suggesting that IL-21 is associated with a type 1 response.