Nuclear Factor Kappa B is a complex of protein which is involved in controlling the DNA transcription, cell survival and cytokine production. Five members of Nuclear Factor Kappa B proteins are expressed by mammals which consist of amino terminal region which is structurally conserved. These five members includes NF-k B1 ( p50 ), NF-k B-2 (p52), Rel A(p65), Rel B and c-Rel. Nuclear Factor Kappa B is present in all cell types and is known to be associated with responding through cellular production to stimuli like bacterial and viral antigens, free radicals, stress and cytokines. The activation of inactive NF-k B is bound to its inhibitor (Ik B) which is phosphorylated during stimulation and later degraded by proteasome. The activated NF-k B is then translocated to the nucleus where it binds to the regulatory site on DNA.  Nuclear Factor Kappa B plays a crucial role in regulation of immune response during infections. Nuclear Factor Kappa B is also know to play a role in nervous system functions which includes learning, plasticity and memory. Nuclear Factor Kappa B are activated by stimulation from many bacterial products and surface proteins, which in turn leads to changes in gene expression and immune responses.

Nuclear Factor Kappa B is often used by the eukaryotic cells for gene regulation involved in cell proliferation and survival. Defects caused in NF-k B can lead to apoptosis and cell death. It also is known for control on various genes associated with inflammation. Nuclear Factor Kappa B is observed to be active in various inflammatory diseases like sepsis, arthritis, asthma, inflammatory bowel disease etc. Activation of Nuclear Factor Kappa B is observed in inflammatory response and cancer. Increased levels of NF- k B are also known to be associated to schizophrenia. NF- k B plays an essential role in induction of pathology by cell activation during development of disease.