Zhao et al. found that circRNA-ATP8B4 from radioresistant GBM-derived EVs sponged miR-766 to facilitate glioma cell radioresistance.35 Further, miR-21 levels in cerebrospinal fluid (CSF)-derived EVs from GBM patients were significantly higher than in controls, while there was no difference in serum-derived EVs miR-21 expression.36 These studies suggested that CSF-derived EV circRNAs were promising biomarkers for glioma diagnosis and prognosis. This evidence concerns the gene ATP8B4 and central nervous system cancer.