He classical NF-B pathway. These responses use NF-B1 (p105), which is constitutively cleaved into p50 and complexes with RelA; this heterodimer can be disinhibited through ubiquitin-mediated degradation of IB by IKK (Kawai and Akira, 2007). In contrast, the alternative pathway uses NF-B2 (p100). NIK activates IKK, which induces proteolytic cleavage of p100 into p52, allowing p52 elB dimers to tran