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Large-scale benchmarking of circRNA detection tools reveals large differences in sensitivity but not in precision


The detection of circular RNA molecules (circRNAs) is typically based on short-read RNA sequencing data processed using computational tools. Numerous such tools have been developed, but a systematic comparison with orthogonal validation is missing. Here, we set up a circRNA detection tool benchmarking study, in which 16 tools detected more than 315,000 unique circRNAs in three deeply sequenced human cell types. Next, 1,516 predicted circRNAs were validated using three orthogonal methods. Generally, tool-specific precision is high and similar (median of 98.8%, 96.3% and 95.5% for qPCR, RNase R and amplicon sequencing, respectively) whereas the sensitivity and number of predicted circRNAs (ranging from 1,372 to 58,032) are the most significant differentiators. Of note, precision values are lower when evaluating low-abundance circRNAs. We also show that the tools can be used complementarily to increase detection sensitivity. Finally, we offer recommendations for future circRNA detection and validation.

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Fig. 1: CircRNA scientific relevance, structure and detection.
Fig. 2: CircRNA detection tools predict a wide variety of circRNAs.
Fig. 3: The precision of circRNA detection tools is generally high and similar, whereas tools largely differ with respect to the number of predicted circRNAs.
Fig. 4: The intersection or union of two circRNA detection tools decreases the number of false positives, or increases the overall number of detected circRNAs, respectively.

Data availability

We anticipate that this study will serve as a future resource for the circRNA community. The information on all predicted circRNAs (n = 315,312), including the large extensively validated circRNA set (n = 1,516), along with the validation results are available in the GitHub repository ( and as Supplementary Tables. The set of circRNAs previously described in databases (Circ2Disease, circad, CircAtlas, circbank, circBase, CIRCpediav2, CircR2disease, CircRiC, circRNADb, CSCD, exoRBase, MiOncoCirc and TSCD) is also included in the GitHub repository. All databases were accessed in the context of a previous study30. Raw FASTQ files are stored in the Sequence Read Archive (PRJNA789110: SRX13414572 (untreated HLF), SRX13414573 (untreated NCI-H23), SRX13414574 (untreated SW480), SRX13414575 (RNase R-treated HLF), SRX13414576 (RNase R-treated NCI-H23), SRX13414577 (RNase R-treated SW480)). Source data are provided with this paper.

Code availability

All of the scripts used to compute the metrics described in the study and generate the figures are available at


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The authors thank S. Lefever for his contribution to primer design in the early stage of this project. The computational resources (Stevin Supercomputer Infrastructure) and services used in this work were provided by the VSC (Flemish Supercomputer Center), funded by Ghent University, FWO and the Flemish Government – department EWI. This work was supported by the Foundation Against Cancer grant STK F/2018/1,267 (M.V., J.V., P.-J.V.), the Standup Against Cancer grant STIVLK2018000601 (J.V., P.-J.V.), two Concerted Research Action of Ghent University grants BOF16/GOA/023 (J.V.), BOF/24J/2021/244 (M.V., J.V., P.-J.V.), the Research Foundation – Flanders FWO grant 1253321N (P.-J.V.), the Fondazione AIRC per la Ricerca sul Cancro Investigator Grant 2017 20052 (S.B.), the Italian Ministry of Education, Universities, and Research PRIN 2017 grant 2017PPS2X4_003 (S.B.), the EU within the MUR PNRR ‘National Center for Gene Therapy and Drugs based on RNA Technology’, Project no. CN00000041 CN3 RNA (S.B.), the ‘HPC, big data and quantum computing’ CN1 HPC (S.B.), the Department of Molecular Medicine of the University of Padova (S.B.), the National Health Research Institutes Taiwan grant NHRI-EX110-11011B1 (T.-J.C.), the German Science Foundation grant DI 1501/13-1 (C.D.), the Wellcome Trust grant WT108749/Z/15/Z (P.F.), the Fondazione Umberto Veronesi Fellowship 2020 (E.G.), the German Federal Ministry of Education and Research grant BMBF 031L0106D (S.H.), the NIH grant R01-NS083833 (E.C.L.), the MSK Core Grant P30-CA008748 (E.C.L.), the German Federal Ministry of Education and Research grant BMBF 031L0164C (P.S.), the Knut and Alice Wallenberg Foundation as part of the National Bioinformatics Infrastructure Sweden at SciLifeLab (J.W.), the National Natural Science Foundation of China (NSFC) grant 31925011 (L.Y.), the Ministry of Science and Technology of China (MoST) grant 2021YFA1300503 (L.Y.), and the National Science Foundation of China (31871589) (C.-Y.Y.).

Author information

Authors and Affiliations



Validation co-author group: M.V., methodology, software, validation, formal analysis, investigation, data curation, writing – original draft, visualization, funding acquisition; J.A., software; O.T., methodology; J.N., E.V.E., K.V., N.Y., investigation; J.V., P.-J.V., conceptualization, methodology, writing – review and editing, supervision, project administration, funding acquisition. CircRNA prediction co-author group: S.B., A.B., C.-Y.C., Q.C., T.-J.C., R.D., C.D., X.D., P.F., E.G., W.G., C.H., S.H., O.I., M.S.J., T.J., E.C.L., J.S., M.S.-K., P.S., G.W., J.W., L.Y., C.-Y.Y., G.-H.Y., J.Z., F.Z., formal analysis and writing – review and editing.

Corresponding author

Correspondence to Jo Vandesompele.

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Nature Methods thanks Eduardo Andrés-León and the other, anonymous, reviewer(s) for their contribution to the peer review of this work. Primary Handling Editor: Rita Strack, in collaboration with the Nature Methods team. Peer reviewer reports are available.

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Supplementary Notes, Data 1–13, Discussion 1, Figs. 1–40 and References.

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Vromman, M., Anckaert, J., Bortoluzzi, S. et al. Large-scale benchmarking of circRNA detection tools reveals large differences in sensitivity but not in precision. Nat Methods 20, 1159–1169 (2023).

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