This supplement provides detailed information on the translation of circular RNAs (circRNAs). The study identifies circRNAs that are translated by ribosomes, termed ribo-circRNAs. The research includes various experiments and analyses to characterize these circRNAs, including their detection by Northern blot, RT-PCR, and polysome profiling. The study also examines the expression levels of circRNAs in different cell types and tissues, and their association with specific protein-coding regions. The results show that ribo-circRNAs are enriched in 5' UTR and CDS regions of their host mRNAs, and that they often contain internal ribosome entry sites (IRES). The study also includes computational analyses of circRNAs, including their lengths, splicing patterns, and conservation across species. The data is supported by multiple figures and tables, including the identification of specific circRNAs, their expression levels, and their association with protein-coding regions. The study provides a comprehensive understanding of the translation of circRNAs and their potential roles in cellular processes.This supplement provides detailed information on the translation of circular RNAs (circRNAs). The study identifies circRNAs that are translated by ribosomes, termed ribo-circRNAs. The research includes various experiments and analyses to characterize these circRNAs, including their detection by Northern blot, RT-PCR, and polysome profiling. The study also examines the expression levels of circRNAs in different cell types and tissues, and their association with specific protein-coding regions. The results show that ribo-circRNAs are enriched in 5' UTR and CDS regions of their host mRNAs, and that they often contain internal ribosome entry sites (IRES). The study also includes computational analyses of circRNAs, including their lengths, splicing patterns, and conservation across species. The data is supported by multiple figures and tables, including the identification of specific circRNAs, their expression levels, and their association with protein-coding regions. The study provides a comprehensive understanding of the translation of circRNAs and their potential roles in cellular processes.