CD5 Helps Aspiring Regulatory T Cells Ward Off Unwelcome Cytokine Advances

The role of co-receptor molecules in the generation of inducible regulatory T cells (iTregs) remains incompletely defined. In this issue of Immunity , Henderson et al. (2015) show that CD5 regulates iTreg cell induction by rendering emerging iTreg cells refractory to signals mediated by effector-differentiating cytokines.