TNF and intervertebral disk degenerative disorder: For instance, some studies have shown that IL1β and TNFα were key inflammatory cytokines in disc degeneration, released by IVD cells in addition to infiltrating inflammatory cells and able to induce catabolic and anti‐anabolic shifts in bovine and human IVDs.38, 39, 40 We report here no increase in expression of these key inflammatory genes, in the absence of disease‐causing conditions or degeneration‐susceptible gene knockout, up to 15 months of age in the mouse NP.