 Eligible study subjects will be randomized into two groups 8-18 weeks after surgery. One group will be maintained on tacrolimus according to the standard of care at our center. In the second group tacrolimus will be converted to sirolimus, with one week overlap between sirolimus therapy and tacrolimus taper. All the deceased donor kidney transplant recipients transplanted at our center who experience DGFSGF are eligible for inclusion in this study, if they meet the inclusionexclusion criteria as detailed later. 