Clinical solid organ transplantation has advanced tremendously over the past two decades. One-year graft survival exceeds 95%, 90% and 80% for kidney, liver and heart grafts, respectively . This improvement has been fueled predominantly by the expanding repertoire of progressively more potent immunosuppressive agents at our disposal. Unfortunately, modern therapies remain imperfect. Despite excellent short-term graft survival rates and low rates of acute rejection attained routinely today, there is an ...