Human neural stem cells target glioma xenograft in the mouse brain. Shown is image of CM-Dil-labeled neural stem cells (red) and immunostaining for SDF-1 (green) in glioma tumor bed. Neural stem cells distribute to SDF-1-rich region, which co-localizes with hypoxic area within tumor. Scale bar, 100 μm. For details, see the article by Zhao and colleagues 1819.