CD8A and irritable bowel syndrome: Inflammatory T cells include CD8+ cytotoxic T cells and CD4+ T helper (Th) cells, while regulatory T cells (Tregs) are anti‐inflammatory T cells.[12] Mounting evidence indicates that immunological dysregulation leading to inflammation is a vital contributor to IBD.[13] Infiltration of inflammatory T cells and excessive inflammatory cytokines are the common denominator of IBD.