NFKB1 and neoplasm of esophagus: More interestingly, we identified that PELI1, a NIK E3 ubiquitin ligase, mediates the Lys48‐linked polyubiquitination and degradation of NIK during radiotherapy and thus negatively regulates the activation of the IR‐induced noncanonical NF‐κB signaling pathways, thereby promoting the radiotherapy‐induced apoptosis of esophageal tumor cells.