OLIG2 and glioma: In accordance with the well-known co-existence of stem cells with their progeny at different stages of differentiation in neural stem cell as well as TSC cultures growing under the form of floating spheres [6], [41], we observed cells immunoreactive for the neural progenitor markers BLBP/FABP7 and Olig2 in oncospheres of the glial tumors examined (12/12 and 5/5 cultures, respectively, Figure 3A, G, H).