Figure 1. Flowchart of the current study. Abbreviations: dCCA: distal cholangiocarcinoma; circRNA: circular RNA; DE circRNAs: differentially expressed circular RNAs; GO: Gene Ontology; KEGG: Kyoto Encyclopedia of Gene and Genomes; qRT-PCR: quantitative real-time polymerase chain reaction; ROC curve: receiver operating characteristic curve; CCK-8: cell counting kit-8; MRE: microRNA response element; miRNA: microRNA; PPI: protein-protein interaction; GSEA: gene set enrichment analysis.