AGO2 and gastric cancer: In our previous work, we have demonstrated that HuR is highly expressed in gastric cancer tissues and cells, while circRNA derived from Argonaute 2 (circAGO2) binds and promotes the recruitment of HuR protein to the 3′-UTR of target genes, and facilitates the proliferation, invasion, and metastasis of gastric cancer cells, suggesting that circRNA can regulate HuR activity in gastric cancer [17].