Finally, to determine whether miR-26a or miR-144 can directly bind to the 3′-UTR of COX-2 mRNA, luciferase reporter activity of WT or MT pMIR-COX-2 plasmid in ESCC cells that overexpressed miR-26a or miR-144 was measured. The gene discussed is PTGS2; the disease is esophageal squamous cell carcinoma.