fig2
From: The role of circRNAs and miRNAs in drug resistance and targeted therapy responses in breast cancer
Figure 2. Biogenesis and functional mechanism of circRNA. First, circRNA is transcribed from genomic DNA by RNA polymerase II or III. Subsequently, during the splicing process, the downstream 5’ splice site of the precursor mRNA (pre-mRNA) is back-spliced with the upstream 3’ splice site to form a circular molecule.
