Background Stem cell therapy is a facet of regenerative medicine that aims to ameliorate the damage caused to the brain by the grafting of healthy “reparative” cells. Pioneering studies implanting mouse neural stem cells (NSCs) into the brains of stroke animals have demonstrated signicant recovery in motor and cognitive tests [1-5]. ese ndings provide a rational approach to the development of a cell based therapy for ischemic stroke. A substantial and consistent supply of allogeneic NSCs is required in order to treat a large patient population. Unfortunately, human NSCs are somatic stem cells and susceptible to genetic and phenotypic changes and loss of biological activity following extensive tissue culture expansion [6-8].