EGFR and cerebral cavernous malformation: RT-qPCR assay demonstrated that the circRNA_102481 expression levels in exosomes were almost equal to those in CCM, but, the levels of circRNA_102481 expression in EGFR-TKIs-resistant cells were significantly higher than in CCM and exosomes (Figure 4A; p<0.05), indicating that extracellular circRNA_102481 was contained in exosomes, which means that circRNA_102481 is mainly secreted to CCM in the form of exosomes.