DNA-binding protein R kappa-B, is a nuclear protein that binds to the DNA consensus sequence 5'-GGGGAATCTCC-3' of NF kappa B. Binding of NFR kappa B is thought to regulate IL-2R alpha (interleukin-2 receptor alpha-chain) gene expression, a critical step in T-cell activation. NFR kappa B exists as 3 isoforms due to alternative splicing and is expressed primarily in the brain, liver, spleen, testis and thymus NFR kappa B gene expression is amplified in acute myeloid leukemia, suggesting a possible role in carcinogenesis.