Thus, Blimp-1 and c-Maf cooperate to control common and distinct gene networks in T cells by specific, direct and shared actions on proinflammatory cytokines, over and above their direct stimulatory effects on Il10. Genes over-expressed in human IBD showed differential expression in the LPLs from H. hepaticus-infected mice with T cell-specific deletion of Prdm1 or Maf, potentially revealing T cell-regulated mechanisms relevant to human disease. This evidence concerns the gene IL10 and inflammatory bowel disease.