Fig. 2

Overview of the four molecular functions of circRNA. a circRNAs can interact with miRNAs, acting as “sponges”. b circRNA have a direct role in translation. c ciRNA can enhance the expression of parent genes; ElciRNA can also enhance the expression of parental genes with U1 snRNP and Pol II. d circRNA can generate functional proteins. Abbreviations: circRNAs circular RNAs, miRNA microRNA, ciRNA circular intronic RNA, Pol II polymerase II, ElciRNA exon-intron circular RNA, U1 snRNP U1 small nuclear ribonucleoprotein particle, mRNA messenger RNA, rRNA ribosome RNA