To clarify the role of USP4 in ESCC, the expression of USP4 in EC patients was analyzed using the TCGA database (https://tcga-data.nci.nih.gov/tcga/) and the GSE26886 dataset (https://www.ncbi.nlm.nih.gov/gds/?term=GSE26886). Here, USP4 is linked to esophageal squamous cell carcinoma.