Due to nuclear translocation of subunits is the key step of activation of NF-κB, we performed nucleus/cytoplasm differential protein extractions, and we firstly showed that in NB cell line SK-N-BE(2), NF-κB could be activated through the p50 subunit following TNF-α treatment, but not p65. The gene discussed is NFKB1; the disease is neuroblastoma.