To do this, we transfected TE‐10 UBQLN4‐OV cells with UBB‐DDK and used anti‐DDK antibody to immunoprecipitate endogenous tagged ubiquitinated‐MRE11A in cisplatin‐treated ESCC cell lines in the presence or absence of MG‐132. Here, UBB is linked to esophageal squamous cell carcinoma.