CD34 and neoplasm: Staining for the vascular progenitor endothelial marker, CD34 [18], revealed the presence of double-positive GFP+ CD34+ cells in both GFP and sh-DUSP8-GFP GSC#1-derived brain tumors, the latter in almost all tumor cells, while double-positive cells were barely detectable in DUSP8-GFP tumor cells, confirming that DUSP8 silencing promotes the acquisition of the molecular determinants for endothelial transdifferentiation (Fig. 6C).