IL4 and inflammatory bowel disease: Considering MSC localization in the spleen and the pivotal role of T cells in IBD, the changes in Th1 (CD4+INF-γ+ T cells), Th2 (CD4+IL-4+ T cells), Th17 (CD4+IL-17A+ T cells), and Treg (CD4+CD25+Foxp3+ cells) cells in the spleen were determined.