MAP3K14/NIK

MAP3K14, better known as NIK (NF-kappaB-inducing kinase), is the master regulator of the non-canonical NF-kappaB pathway. In resting cells NIK is continuously ubiquitinated and degraded by a TRAF3-cIAP1/2 complex; stimulation of receptors such as CD40, RANK, LTbetaR, and BAFF-R stabilizes the kinase, allowing it to phosphorylate IKKalpha, which then processes NF-kappaB2 p100 into p52 and activates RelB. NIK thereby controls lymphoid organogenesis, B-cell survival, osteoclast differentiation, and the formation of tertiary lymphoid structures in disease. Constitutive activation through TRAF3 loss occurs in multiple myeloma and certain lymphomas, positioning NIK as a therapeutic target in these hematologic malignancies and in autoimmune settings.