As shown in Figure 4C, the expression of stemness markers were markedly different in the different types of GBM primary cultures: some expressed markers for all types of neural cells (i.e. Olig2, GFAP and β-tubulin), and others expressing limited amount of neural markers (i.e. the neuronal β-tubulin) while others expressed high level of nestin and β-tubulin and low level of Olig2 and GFAP. This evidence concerns the gene OLIG2 and glioblastoma.