METRN and glioblastoma: ldrEXOs promoted proliferation, radioresistance, apoptosis radioresistance, invasion, and migration abilities of glioblastoma cell lines (β) while knockdown of circ-METRN (γ) or up-regulation of miR-4709-3p (δ) attenuated these abilities of glioblastoma cell lines previously treated with ldrEXOs (Figure 5A-E).