CircMMP9 could interact with both AUF1 and miR-149, and block the inhibitory effect of AUF1 and miR-149 on the 3’-UTR of MMP9 to enhance the stability of MMP9 mRNA, thereby promoting the metastasis of oral squamous cell carcinoma [42]. The gene discussed is HNRNPD; the disease is oral cavity squamous cell carcinoma.