The world of non-coding RNAs is continually expanding, revealing new layers of biological complexity and therapeutic potential. Among the most exciting discoveries are circular RNAs (circRNAs). Unlike their linear counterparts, circRNAs form covalently closed loops, granting them remarkable stability and unique functions in gene regulation. This intrinsic stability, coupled with their presence in biofluids, positions circRNAs as powerful new candidates for biomarker discovery and novel therapeutic targets. The Challenge of CircRNA Analysis from Biofluids Despite their immense promise, accurately isolating and quantifying circRNAs, especially from challenging biofluid samples like plasma and serum, has presented significant technical hurdles. These samples typically contain very low concentrations of circRNAs alongside a vast excess of highly abundant linear RNAs (like ribosomal [...]