To investigate the relationship between the expression of UBQLN2 and the radiosensitivity of ESCC cells, we first detected the expression of UBQLN2 in KYSE-30, KYSE-70, KYSE-150, and Ec109 ESCC cell lines and normal human esophageal epithelial cells HET-1A. Here, UBQLN2 is linked to esophageal squamous cell carcinoma.