Kidney transplantation is the best treatment for patients with kidney failure, but improvements in long-term graft and patient survival have plateaued during the last few decades.1,2 Achieving the right balance between sufficient immunosuppression and risk for developing drug-related side effects such as infection, cancer, and cardiovascular diseases is difficult. Building on an increasing understanding of immunoregulatory cells and the revolution in cell-based therapies for cancer treatment, the time has come to test cell-based adoptive immunotherapy in transplant recipients to improve outcomes.