FIGURE 1.

Purpose of circular RNA. (A) Interact with RNA‐binding proteins: When circRNAs bind to RBPs, RNA‐protein complexes might result. (B) Circular RNAs exhibit a miRNA sponge effect by having many miRNA binding sites, which act as ceRNAs when bound to miRNAs. (C) Translation role of circRNA: The eukaryotic ribosomal 40S small subunit can bind to circular RNAs through this location to guide the synthesis of proteins. Circular RNAs have an IRES. (D) Regulation of gene expression; ceRNA, competing endogenous RNA; circRNA, circular RNA; IRES, internal ribosome entry site; miRNA, MicroRNA; RBP, RNA‐binding protein; snRNA, small nuclear RNA.