CXCL8 and nasopharyngeal carcinoma: We also investigated whether exogenous IL-8 stimulation decreases NPC cell radiosensitivity, and found that exogenous IL-8 stimulation markedly decreased radiosensitivity of radiosensitive CNE-2 cells as demonstrated by a clone survival assay [AUC1.28 (1.5 ng/mL IL-8) vs.1.01(control), P < 0.05; RPF = 1.27][AUC 1.48 (4.5 ng/mL IL-8) vs.1.01(control), P < 0.05; RPF = 1.46] (Figure 4D).