have pointed out that 8 circRNAs (circ_COL1A2, circ_VCAN, circ_PTN, circ_SMO, circ_PLOD2, circ_GLIS3, circ_EPHB4 and circ_CLIP2) are upregulated in GBM cells.20 This evidence concerns the gene GLIS3 and glioblastoma.