Similarly, CD137 is ectopically expressed on nasopharyngeal carcinoma (NPC) and rhabdomyosarcoma (RMS) cells, and CD137 signaling induces their secretion of IL-6 and IL-8 which promotes metastasis and indicates a poor prognosis 19, 20. The gene discussed is TNFRSF9; the disease is nasopharyngeal carcinoma.