PROM1 and glioblastoma: The tumorigenicity of CD15+ cells is 100 times higher than that of CD15- cells in human glioblastoma, where all CD15+ cells were also found to be CD133+, while most CD133+ cells also expressed CD15, suggesting that CD15 is highly likely to be another surface marker of glioblastoma stem cells (Son et al., 2009).