Further detection revealed that circ-METRN level (Mean±SD) in Glioblastoma tissues was 8.499±0.233 while circ-METRN levels (Mean±SD) in serum exosomes were 1.025±0.067 (before operation), 0.995±0.071 (before radiotherapy), 2.560±0.164 (during the first week of radiotherapy), and 1.737±0.122 (after radiotherapy), respectively. Here, METRN is linked to glioblastoma.