CAFs were also noted to be in close proximity to cells expressing glioblastoma stem cell (GSC) marker CD44 (Figure 2H) and were enriched in the perivascular niche where GSCs reside (34) based on their proximity to endothelial cells expressing CD34 (Figure 2H) or CDH5 (Supplemental Figure 15A). This evidence concerns the gene CD44 and glioblastoma.