PROM1 and glioblastoma: To identify novel genes that CD133+ GSCs require for tumorigenicity, we performed an RNA-sequencing (RNA-seq) comparison of FACS-sorted CD133+ and CD133− cells in duplicates from a primary human GBM culture, GBML8 (GEO accession number GSE85297) (Figure 1a).27 We identified 266 upregulated and 48 downregulated genes in CD133+ cells (Supplementary Tables 1a and b) (fold-change cutoff: 1.5; false discovery rate <0.05).