Recent studies have given well-defined differentiation protocols, which can be used to guide stem cells into specific cell lineages as neurons, cardiomyocytes and insulin-secreting cells. Moreover, these derived cells have been useful in different animal models. In this regard, insulin-secreting cells derived from R1 mouse embryonic stem cells restore blood glucose concentrations to normal when they are transplanted into streptozotocin-induced diabetic animals. Our group has isolated stem cells (CD34 positive subset of stem cells) that are capable of differentiating into multiple tissue types ex vivo. In defined conditions, in culture, about 40 percent of the cells produce insulin and reduce blood sugar levels in streptozotocin-induced mice.