KDR and cancer: Bioinformatics analysis showed circCCDC66-miR-320a/b axis was involved in regulating multiple cancer-related pathways, such as Protein metabolism, Regulation of nucleobase, PDGF receptor signaling network, VEGF and VEGFR signaling network, EGFR-dependent Endothelin signaling events, Sphingosine 1-phosphate (S1P) pathway, Proteoglycan syndecan-mediated signaling events.