Regarding the clinical significance of tumor PD-L1 expression and CD4+ T lymphocyte infiltration in eCCA, our results demonstrated, for the first time to the best of our knowledge, that high PD-L1 expression on the tumor and low tumor infiltration of CD4+ T lymphocytes were independent poor prognostic factors by multivariate analysis, although a correlation between these two factors was not identified. Here, CD4 is linked to neoplasm.