PSMD2 and esophageal squamous cell carcinoma: Molecular approaches including DAPgreen staining, 5-Ethynyl-2ʹ-deoxyuridine (EdU), cell counting kit 8 (CCK8), colony formation, transwell assays, and cell transfection, xenograft model, immunoblotting and Immunohistochemical analysis were used to investigate the roles of PSMD2 in ESCC cells.