Multiple immune cells contribute to tissue repair and transplant tolerance. T cells, highlighted here, contribute to both tissue repair and transplant tolerance through production of the immunosuppressive cytokines interleukin-10, transforming growth factor β (TGF-β), and interleukin-35 by regulatory T cells (Tregs) and in the context of a wound secrete growth factors specific to the tissue. Other T-cell types, such as type 2 helper T (Th2) cells, promote tissue repair through production of cytokines, including interleukin-4.