Experiments with human neurogenic precursor cells have revealed the ability of these cells to be carried in culture and differentiate into neurons, astrocytes and oligodendrocytes. Neural stem cells have also been shown to engraft, migrate and differentiate in rodents in vivo. However, little is known about the surface antigens present on human central nervous system stem-cells (CNS-SC), affecting the ability of researchers to easily isolate and follow the development of these cells. In the 19 December issue of Proceedings of the National Academy of Sciences, Uchida et al. (Proc. Natl. Acad. Sci. USA 97, 14720–14725) report the creation of novel antibodies against CNS-SC surface molecules that can be used in fluorescent-activated cell-sorting analysis to isolate these cells from human fetal brain tissue. They demonstrated that this approach could be used to isolate a specific population of self-renewing CNS-SC. These cells were shown to initiate neurosphere cultures and differentiate into neurons and glia cells in vitro. When expanded cells were transplanted into the lateral ventricles of newborn mice, they underwent self-renewal, migration and neural differentiation in different areas of the brain. The picture shows the differentiation capacity of clonally derived neurosphere cells. Progeny of single cell-derived neurospheres differentiated into neurons (green) and astrocytes (red), while cell nuclei are stained blue. Uchida et al. showed that at 7–12 months post-transplant, the human CNS-SC could still be detected, were still able to respond to host microenvironment cues and were not neoplastic. The ability to directly isolate human CNS-SC will advance the testing of these cells in animal models of neurological disease as well as in preclinical studies for transplantability and tumorigenicity.