I don't know much about circRNAs so excuse my naiveness - I wonder if it could be used for gene replacement therapy in the future? Something like, if there is a stop codon somewhere in the middle of a gene, the small piece of circRNA, contains the correct version of that stop codon and is introduced into the cell. Next thing you know, that stop codon is by passed, as the transcription or translation machinery builds an entire good sequence using the DNA and the good code circRNA. Also, since they are resistant to degradation, they might be good shuttle vehicles for tiny 'good copy' exons.