CD4 and inflammatory bowel disease: While MAIT cells can have a Th1-like cytokine repertoire, and be relatively plastic in their behavior, MAIT cells share many properties with Th17 cells, an IL-17A-producing CD4+ population of T cells that has been much more extensively studied than MAIT cells in IBD [38,39], and has been implicated in the pathogenesis of multiple autoimmune diseases and disease models [40–42].