CHUK and viral infectious disease: Following appropriate cellular activation, via cytokines, chemokines, growth factors, viral infection, etc., a downstream signaling pathway is initiated from the receptor-ligand engagement that usually culminates in the activation of the appropriate IκB kinase (IKK) complex (IKKα and IKKβ are the catalytic subunits, and IKKγ/NEMO is a structural regulator) and the phosphorylation of the critical serines, S32 and S36, on the IκBα molecules.