NFKB1 and Ewing sarcoma: In the present report, we also find an early and transient increase in intracellular oxidants, which is accompanied by an activation of the transcription factor NF-κB. We show indeed that addition of antioxidants prevents the cytotoxicity of melatonin in Ewing's sarcoma cells, supporting the involvement of an increase in such oxidants in melatonin-induced cell death.