SH3GL2 and neoplasm: This circRNA enters the cytoplasm of the cells and binds to EZH2 to reduce its intranuclear transport, decrease the formation of H3K27me3, and promote the transcription of SH3GL2 to increase the level of SH3GL2, which can negatively regulate ZO-1/occludin; these events eventually destroy the endothelial barrier function and promote tumour angiogenesis [30](Figure 4).