Cytokine-independent activation of STAT5 promotes the persistence and function of CD4+ regulatory T cells

. This STAT5 activator (aSTAT5) enhanced Treg engraftment in mice and prevented the onset of colitis. Tregs that expressed aSTAT5 better maintained their lineage and were more effective at suppressing pathogenic inflammatory T cells. Our findings demonstrate a new approach to equip Tregs with the signals they need to maintain their suppressive capacity.