CD4 and inflammatory bowel disease: The narrowly defined IBD includes Crohn’s disease (UC) and ulcerative colitis (CD).1-3 The pathogenesis of IBD is unclear, which may be related to immune, heredity, infection and mental factors etc.4,5 Immunity, especially the relationship between intestinal immunological environment and IBD is the study focus.6 T helper 17 cells (Th17) is a group of newly discovered CD4+ positive T lymphocyte subset, mainly mediating chronic inflammation and autoimmune diseases.7-9 The present study has shown that Th17 is abnormally expressed in IBD patients.