Studies have revealed that the expression of most circRNAs is greater in normal brain tissues than in GBM tissues, with only a few displaying elevated levels in tumor samples.55 Notably, circ-SMARCA5 is significantly downregulated in GBM, whereas circ-CFH and circ_0012129 are upregulated,56 indicating their distinct roles in tumor progression. This evidence concerns the gene SMARCA5 and glioblastoma.