TNF and intervertebral disk degenerative disorder: The nuclear factor‐kappa B (NF‐κB) signalling pathway has been demonstrated as a crucial mediator of the IDD process and the therapeutic target in disc degeneration.12, 14, 15, 16, 17 Pro‐inflammatory cytokines activate the NF‐κB signalling and downstream pathways, thereby participating in inflammatory response, cell apoptosis and ECM metabolism.10, 17 In the NF‐κB signalling pathway, TNF‐α binds to its receptor and transduces the signal to activate the IκB kinase (IKK) complex, which is composed of three units: IκB kinase α (IKKα), IκB kinase β (IKKβ) and IκB kinase γ (IKKγ).