The IKK (IκB kinase) complex is the core of NF-κB signal transduction, crucial for promoting the translocation of NF-κB from the cytoplasm to the nucleus and activating gene expression. This family consists of IKKα (IKK1), IKKβ (IKK2), and IKKγ (NEMO), with the former two possessing kinase activity and the latter regulating complex function. Located in the cytoplasm, IKK responds to inflammatory and microbial infection signals, phosphorylates IκBα, and releases NF-κB. IKK is widely expressed and essential for immunity, growth, and inflammatory responses. Specific expression and mutations are associated with autoimmune diseases, inflammation, and cancer, with IKKβ activation closely linked to disease progression, while IKKα's role varies depending on context, making it a target for inflammation and cancer therapy.