FLI1 and nasopharyngeal carcinoma: To explore the effect of FLI1 on radiosensitivity of NPC, we stably overexpressed FLI1 in CNE1 and SUNE1 cells which had lower FLI1 levels and were more radiosensitive, and knocked down FLI1 in 5-8F and 6-10B cell lines which had higher FLI1 levels and were more radioresistant (Fig. 2A, B and Additional file 1: Fig. S2A–E).