Normally, metabolic and ischemic insults stimulate repair and regeneration. In diabetes, however, these processes are impaired. Recent advances in cell reprogramming hold great promise for future cell replacement therapies. How are specific populations of stem/progenitor cells affected by diabetes? Are these abnormalities reversible through optimal diabetes treatment or therapies targeted to stem/progenitor cells? Will new cell reprogramming techniques, such as induced pluripotent stem (iPS) cells, lead to individualized cell therapy? A barrier to understanding the impairments includes the known heterogeneity within stem cell compartments, specifically mesenchymal stem cells. Protocols are needed for the culture of progenitor cells and their thorough analysis, including genetic, epigenetic, and transcription factor analysis of individual cells and stem cell populations. Can ex vivo therapies be developed that reverse stem cell dysfunctions? Though iPS cells created with current protocols are unlikely to be transferred to people for treatment, these protocols offer the opportunity to take cells from individuals and direct their differentiation into cell-based models of DN.