All study subjects are followed for safety for one year. An independent Data Monitoring Committee (DMC), composed of 3 members who have training in medicine and/or organ transplantation, will review eligibility and safety data within 2 weeks after each islet transplantation and every two months thereafter. An independent monitor, who is knowledgeable about Good Clinical Practice (GCP) guidelines and regulations, monitors the study for compliance with 21 CFR and according to ICH GCP Guidelines. Within the Clinical Research Center, representatives of the Scientific Advisory Committee and the Research Subject Advocacy Program monitor safety. These entities report to the UIC Institutional Review Board (IRB), which also reviews safety data annually and on occurrence of serious adverse events. The principal investigator also reports serious adverse events to the US Food and Drug Administration (FDA).