CD45RBhigh CD4+ naive T cells, which are presumably selected as non-self-reactive T cells in the thymus, efficiently induce colitis in recipients, while CD25−CD45RBlow CD4+ T cells, which are composed of memory-like T cells and a small amount of Tregs, do not.40 Ono et al.41 showed that the depletion of GITRhigh T cells resulted in a more aggressive autoimmune disease with wider organ involvements than that of CD25+ T cells by further reducing Foxp3+ T cells (~2% vs ~6%). The gene discussed is FOXP3; the disease is colitis.