Dr. Andrews the genetics of hematopoietic (blood-generating) stem cells. Currently, he researches factors that affect interactions of transplanted (allogeneic) CD34+ hematopoietic stem cells with progenitor cells. Hematopoietic stem cells generate all types of blood cells while progenitor cells are precursors of more specific types. His research may contribute to in-utero therapies for disorders that can cause developmental disabilities. For example, if transplanted CD34+ hematopoietic cells can be engrafted with progenitor cells in utero, they may be effective in treating leukodystrophies, rare degenerative brain disorders caused by defects in the growth or development of the myelin sheaths that insulate nerve fibers.