FIGURE 1.

The biogenesis and functions of circRNAs. A, Pre‐mRNA is canonically spliced into linear RNA through the removal of introns. B, CircRNAs are derived from non‐canonical splicing events. Three types of circRNA are formed. C, The biogenesis of circRNAs. CircRNAs can be miRNA sponges and modulate miRNA activity. CircRNAs can bind to RBPs and affect their functions and translocations. Certain circRNA regulates transcription and encodes proteins. In addition, circRNA‐derived pseudogenes can insert into the genome. D, The degradation of circRNA. CircRNAs are globally degraded by RNase L in early cellular innate immune responses. E, The elimination of circRNA. CircRNAs can be eliminated into the extracellular space by exosomes