Circular RNAs (circRNAs) are a type of single-stranded RNA molecules that 
normally do not encode proteins. circRNAs are involved in many physiological 
processes as well as the pathogenesis of diseases. Cardiac fibrosis is 
increasingly recognized as a pathological force in advanced heart diseases. A 
growing number of studies have reported that the occurrence and development of 
cardiac fibrosis is closely associated with the regulation of circRNAs. This 
review summarizes the current understanding of circRNA biogenesis and function 
and will highlight the recent updates regarding the involvement of circRNAs in 
cardiac fibrosis, and their potential as emerging biomarkers and therapeutic 
targets.