UBQLN4 and esophageal squamous cell carcinoma: 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.