PTGDR and cervical cancer: To investigate the biological function of circCDKN2B-AS1 in the malignant phenotype of cervical cancer cells, we knocked down circCDKN2B-AS1 by using two specific siRNAs in SiHa and CaSki cells and found that circCDKN2B-AS1 downregulation did not affect the expression of the linear forms of CDKN2B-AS1 (Fig. 2a) but inhibited cellular proliferation, migration and invasion, and promoted cellular apoptosis (Fig. 2b-f,Additional file 5: FigureS2).