Transplantation is a good treatment for people with end-stage kidney disease. However, there is still much to learn about how to best care for the transplanted kidney and keep it working for a long time. Unless a person receiving a kidney from someone else takes drugs that reduce immune function, the kidney will be rejected. Those drugs must be continued life-long and cause many issues. Therefore, tolerance of the transplanted kidney, without chronic rejection and without the need for permanent immunosuppressive drug treatment, is a highly desirable goal. If this can be achieved, it would make "one kidney for life" possible.