The Cellular Hematology Scientific Research Group, Division of Blood Diseases and Resources, NHLBI, the Hematology Program, Division of Kidney, Urologic, and Hematologic Diseases, NIDDK, and the Repair and Plasticity Program, NINDS announce the availability of a Request for Applications (RFA) on the above subject. The objective of this initiative is to promote the thorough exploration and characterization of stem cell plasticity in hematopoietic and non-hematopoietic tissue. Research efforts are needed to test stem cell plasticity in a rigorous manner. It is of particular importance to characterize cellular and molecular mechanisms that lead to the capacity of adult stem cells with hematopoietic potential to express other potentials and precursor cells of adult non-hematopoietic tissues to express hematopoietic potential. Other areas of high interest include the ability of stem cells from non-neuronal tissues to differentiate along neuronal and glial lineages.