TNF and Intervertebral disk degeneration: Previous studies have also reported elevated pro-inflammatory cytokines such as ILs-6, −7, and −8 in tissues of patients undergoing surgery for back pain (Altun, 2016; Zhang et al., 2016); associations between TNF-α, IL-6, and IL-8 with back pain (Wang et al., 2008; Brinkley et al., 2009; Kraychete et al., 2010; Pedersen et al., 2015; Queiroz et al., 2017); and a possible key role for TNF-α and IL-1β in the pathology of intervertebral disc degeneration (Li et al., 2014).