In order to more fully assess the functional capacity of TR cells lacking Gpr83 expression, we used a T-cell transfer model of colitis, in which a severe T helper type 1 (Th1)-mediated inflammation within the colon is induced following the transfer of naïve CD4+ CD45RBhi T cells into immunodeficient recipients.24 The co-transfer of CD4+ CD45RBlo CD25+ TR cells is sufficient to prevent the development of disease. The gene discussed is CD4; the disease is colitis.