||The NF-κB/Rel family of transcription factors is comprised of several structurally-related proteins that form homodimers and heterodimers and include p50/p105, p52/p100, RelA (p65), c-Rel/NF-κB. Members of this family are responsible for regulating over 150 target genes, including the expression of inflammatory cytokines, chemokines, immunoreceptors, and cell adhesion molecules. Because of this, NF-κB has often been called a"central mediator of the human immune response. Acting as dimers, these transcription factors bind to DNA sequences, collectively called κB, sites thereby regulating expression of target genes. In most cells, Rel/ NF-κB transcription complexes are present in an inactive form in the cytoplasm, bound to an inhibitor IκB. Certain stimuli result in the phosphorylattion, ubiquitination and subsequent degradation of IκB proteins thereby enabling translocation of NF-κB into the nucleus. The most common Rel/NF-κB dimer in mammals contains p50-RelA (p50/ p65) heterodimers and is specifically called NF-κB. One of the target genes activated by NF-κB is that encoding IκBα. This feedback mechanism allows newly-synthesized IκBα to enter the nucleus, remove NF-κB from DNA and transport it back to the cytoplasm thereby restoring its inactive state. The importance of Rel/NF-κB transcription factors in human inflammation and certain diseases makes them attractive targets for potential therapeutics.