Rabbit Anti-Human NFKB1 polyclonal antibody for IHC-P. NF kappa B is a heterodimer consisting of a 50kDa DNA binding subunit and a 65kDa transactivating subunit (RelA) . P50 subunit of NFkB has an isoform and both the proteins of 105 and 100kDa respectively. The p50/p65 heterodimer is present in the cytoplasm in active form bound to its inhibitor, IkB. Upon stimulation of cells with stimuli like LPS, Interlekin-1, IkB gets phosphorylated and degraded by proteosomes releasing the activated NFkB which goes to the nucleus inducing gene expression.