14 have been identified to promote cervical cancer progression, suggesting the important role of circRNAs in cervical cancer tumorigenesis. As for circ_0003221 (also known as circPTK2, chr8:141856358–141900868), it has been demonstrated to be overexpressed in cervical cancer cells. 15 Nevertheless, the role of circ_0003221 in cervical cancer remains largely unclear. Large evidence has shown that circRNAs can serve as competing endogenous RNAs (ceRNAs), also known as microRNA (miRNA) sponges, via competitively binding to miRNA response elements, thereby regulating the expression of downstream target genes. 16,17 Based on this regulation, circRNAs can function as miRNA sponges to regulate the expression of target genes, forming a regulatory circRNA-miRNA-mRNA network. MiR-758 has been identified to serve as a tumor-suppressing miRNA in cervical cancer.