Cells from the canine glioma cell line J3T and the human glioma cell line LN18 contain a small subpopulation of CD133+ cells (1.17 ±0.58 % (n = 8) and 2.07 ±0.43 % (n = 4), respectively), that are significantly better at forming spheres (Figure 1A and 1B), and express higher levels of the embryonic stem cells markers Oct4, Nanog and STAT3 (Figure 1C) than CD133- cells (similar results were obtained for LN18 CSC, data not shown). This evidence concerns the gene NANOG and central nervous system cancer.