POLR2B and glioma: Upon determining the mechanism by which only the expression level of circPOLR2B in the nucleus regulates the biological behavior of GSCs, we analyzed data from the GTEx project and TCGA database and found that POLR2B expression is higher in glioma tissues than in normal tissues (Fig. 4A) and that compared to that in HA, the expression of POLR2B was upregulated in GBM cells and was more pronounced in GSCs (Fig. 4B).