CLK3 and cervical carcinoma: qRT-PCR results showed that the half-life of circCLK3 exceeded 24 h in SiHa and HeLa cells, while that of CLK3 mRNA was <6 h (Fig. 1g), and that compared with linear mRNA CLK3, circCLK3 was more capable of resistance to digestion of RNase R (Fig. 1h), indicating that circCLK3 is highly stable in cervical cancer cells.