CTLA4 and inflammatory bowel disease: Uraushihara et al. 24 reported that GITR+CD25−CD4+ cells: (1) exert suppressive activity in inflammatory bowel disease; (2) express elevated levels of CTLA‐4 as well as GITR+CD25+CD4+ cells; (3) suppress the proliferation of CD4+ cells in vitro; and (4) produce higher levels of IL‐10 and TGF‐β.