Forkhead box P3 (FOXP3) is a significant transcriptional regulator involved in the development and function of CD4+ regulatory T (Treg) cells; an increased number of Foxp3+Tregs and high levels of their signature cytokines TGF-β and IL-10 have been identified in the inflamed intestinal wall of IBD patients and also highlighted in a murine model with colitis [88,89]. Here, FOXP3 is linked to inflammatory bowel disease.