Recombinant HEK293 cell line expressing a full length human CD137 (NM_003811). The NF-κB luciferase reporter construct is stably integrated into the genome. The firefly luciferase gene is controlled by 4 copies of NF-κB response element located upstream of the TATA promoter. Following activation by human CD137 ligand, NF-κB transcription factors bind to the DNA response elements to induce transcription of the luciferase gene.