Therapeutic opportunities for manipulating TReg cells in autoimmunity and cancer

Regulatory T (TReg) cells are essential mediators of immune homeostasis. They are attractive targets for steering the immune system in desired directions — arming it to destroy cancer cells or downregulating it in autoimmunity. In this Review, Daniel and von Boehmer discuss how molecular insights into the generation and proliferation of these cells can be exploited for new therapeutic approaches.