Photomicrograph of the GBM-derived tumor that arose following stereotactic intracranial transplantation of CD133-positive tumor cells. High power view of transplanted human CD133-positive cells grown in the brain of an immune-deficient NOD/SCID mouse is shown (40x objective). The tumor has a solid growth pattern. The tumor cells have darkly stained nuclei and scant cytoplasm. Nucleoli are not easily identified. Tumor necrosis and vascular proliferation are evident similar to the patient tumor shown in Figure 1B.