According to our findings, CLCN4 was highly expressed in 20 tumor types, such as ACC, CHOL, COAD, UCEC, etc. Higher CLCN4 levels were associated with poor OS (MESO, UCEC), short DSS (BLCA, MESO, and UCEC), low PFS (BLCA, UCEC), bad DFS (THCA, UCEC), Interestingly, across all four categories of prognostic factors, CLCN4 represents an obvious risk factor for UCEC, so we choose the endometrial cancer for in-depth analysis. Here, CLCN4 is linked to neoplasm.