NIK SMI1 is a potent, selective NF-κB inducing kinase (NIK) inhibitor, which inhibits NIK-catalyzed hydrolysis of ATP to ADP with IC50 of 0.23±0.17 nM. NIK SMI1 is a click chemistry reagent, it contains an Alkyne group and can undergo copper-catalyzed azide-alkyne cycloaddition (CuAAc) with molecules containing Azide groups.