Table 1.

Characteristics of different types of circRNAs

Name	Type	Location	Joint site	Sequence feature	Function
ciRNA	Intron	Nucleus	2’-5’ phosphodiester bond	Enrichment of 5’ splice site containing 7 GU motif, enrichment of 3’ branch site containting 11 C motif	Regulation of gene transcription
EIciRNA	Exon-intron	Nucleus	3’-5’ phosphodiester bond	Circularization exons containing the reverse complementary sequence of introns and selective circularization	Regulation of gene transcription
ecRNA	Exon	Cytoplasms	3’-5’ phosphodiester bond	Circularization exons containing the reverse complementary sequence of introns and selective cyclization	MiRNA sponges; interaction with RBP; translation

ecRNA: Exonic circRNA; ciRNA: Intronic circRNA; EIciRNA: Exon-intronic circRNA.