Molecular Network-Based Identification of Circular RNA-Associated ceRNA Network in Papillary Thyroid Cancer, Abstract Circular RNAs (circRNAs) have displayed dysregulated expression in several types of cancer. Nevertheless, their function and underlying mechanisms in papillary thyroid cancer (PTC) remains largely unknown. This study aimed to describe the regulatory mechanisms in PTC. The expression profile of circRNA was download from the Gene Expression Omnibus (GEO) database. The mRNA and miRNA data of PTC was downloaded from The Cancer Genome Atlas (TCGA) database. The circRNA-miRNA-mRNA network by Cytoscape. The interactions between proteins were analyzed using the STRING database and hubgenes were identified using MCODE plugin. Then, we conducted a circRNA-miRNA-hubgenes regulatory module. Gene Ontology (GO) and Kyoto Encyclopedia of Gene and Genomes (KEGG) pathway analysis were conducted using R packages “Clusterprofile”. We identified 14 differential expression circRNAs (DEcircRNA), 3106 differential expression mRNAs (DEmRNA), 142 differential expression miRNAs (DEmiRNA) and in PTC. Twelve circRNAs, 33 miRNAs, and 356 mRNAs were identified to construct the ceRNA network of PTC. PPI network and module analysis identified 5 hubgenes. Then, a circRNA-miRNA-hubgene subnetwork was constructed based on the 2 DEcircRNAs, 3 DEmiRNAs, and 4 DEmRNAs. GO and KEGG pathway analysis indicated DEmRNAs might be associated with PTC onset and progression. These ceRNAs are critical in the pathogenesis of PTC and may serve as future therapeutic biomarkers.