Mouse monoclonal antibody 14H2 recognizes human Nuclear factor- kB (NF-kB )p65, also called RelA-p65. NF-kB is considered to be one of the main transcription factors driving the expression of genes of inflammatory and immune responses, regulated by a divers panel of modifications to exerts it divers function. Other family members in mammals are RelB, c-Rel, NF-kB1 and NF-kB2, the latter two are processed in respectively p105/p50 and p100/p52. NF-kB functions as a dimer and they all share a Rel homology domain, responsible for DNA binding and dimerization. The activity of NF-kB is regulated by interaction with a family of inhibitory IkB proteins. The different NF-kB complexes have their own individual IkB proteins. In general NF-kB is present as IkB -complex in the cytoplasm. When the inflammatory response is triggered by eg proinflammatory cytokines or LPS, this leads to phosphorylation of IkB via IKK complex (IKKα, IKKβ and NEMO) leading to release of NF-kB from the complex. Subsequently, NF-kB enters the nucleus where it activates gene expression. NF-kB activation consist out of two activation pathways. The canonical pathway is the most common one. In the canonical pathway, IκBα is phosphorylated in an IKKβ- and NEMO-dependent manner, which results in the nuclear translocation of mostly p65-containing heterodimers. In contrast, the non-canonical pathway involves IKKα-mediated phosphorylation of p100 associated with RelB, which leads to partial processing of p100 and the generation of transcriptionally active p52-RelB complexes. Besides inflammation, auto-immune and metabolic diseases, NF-kB is involved in tumor development. Related inflammatory diseases are IBD, rheumatoid arthritis, SLE, diabetis, celiac disease, multiple sclerosis and Parkinson’s disease.