TNF and intervertebral disk degenerative disorder: Previous work provided evidence, that the expression of proinflammatory cytokines such as TNF-α, IL1β, IL-6, and IL-8, is associated with the disease activity of IDD in human subjects and animal models (Le Maitre et al., 2005, 2007b; Bachmeier et al., 2007; Hoyland et al., 2008; Freemont, 2009; Freeman et al., 2013; Purmessur et al., 2013; Andrade et al., 2016; Sutovsky et al., 2017).