Islet transplant will be performed under Anti-Thymocyte Globulin (ATG, Thymoglobulin®) induction immunosuppression (5 doses, day -2 prior to transplant to day 2 post-transplant). Maintenance mycophenolate mofetil (MMF) therapy (1-2 g/day as BID dosing) will be started on Day -1 pre-transplant. Tacrolimus will be administered orally twice daily on Day 1 post-transplant to maintain a trough level of 10-12 ng/mL for 3 months, then 6-10 ng/mL thereafter. Etanercept will be given IV before the islet transplant (50 mg), and then at 25 mg (subcutaneously) on post-operative day (POD) +3, +7 and +10.