The purpose of this study is to determine the best immunologic match between potential living donors and their recipients. We will create a mouse with the exact immunologic makeup of the potential living kidney transplant recipient. We will replicate these mice so we have as many mice as the potential recipient has living donors. We will take blood from each potential living donor and inject peripheral blood mononuclear cells (PBMCs) into the recipient?s mouse model. We will use genomic, proteomic and immunological signatures of human allograft rejection (foreign transplantation antigens, allogeneic recognition) established in our laboratory as well as immunobiological signatures of acceptance of the transplant (self-antigens, autologous, and combination), which also will be established in our laboratory to determine the optimal living-donor for the kidney transplant recipient.