CCDC66 and colorectal carcinoma: In another study, using RNA-seq data, circRNAs were also found to be significantly downregulated in CRC.41 In contrast, Hsiao et al.39 found several upregulated circRNAs in CRC, among them a circRNA derived from the CCDC66 gene, which may function as an oncogenic decoy by binding miRNAs that mainly target oncogenes.