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Background: Programmed death-1 (PD-1) receptor/PD-1 ligand (PD-L1) pathway negatively regulates T-cell-mediated responses.The prognostic impact of PD-L1 expression needs to be defined in esophagus cancer (EC).Patients and methods: Formalin-fixed paraffin-embedded tumor samples from 150 patients with EC were retrieved.PD-L1 expression was evaluated by immunohistochemistry using a rabbit monoclonal anti-PD-L1 antibody .PD-L1 positivity on tumor cell membrane was defined as ≥5% of tumor cell membrane staining.