NGF can be upregulated by proinflammatory cytokines which are present in disc degeneration in vivo.40, 41, 42 To determine the effect of Link N on IL‐1β‐stimulated NGF release, normal AF cells were exposed to IL‐1β, Link N, or coexposed with Link N and IL‐1β. This evidence concerns the gene NGF and intervertebral disk degenerative disorder.