To further study whether TUG1 exerted its functional role in DDP resistance of ESCC cells through regulating PDCD4 expression, ECA109/DDP and EC9706/DDP cells were transfected with si-con, si-TUG1 or si-TUG1 + si-PDCD4. The gene discussed is TUG1; the disease is esophageal squamous cell carcinoma.