TNF and intervertebral disk degenerative disorder: To date, many studies have focused on the mechanism by which major inflammatory cytokines such as TNF‐α and IL‐1β cause disc degeneration.8, 15, 16, 17 These inflammatory cytokines have many reported roles in acute phase inflammation such as infection, tumor, and trauma.18 TWEAK, by contrast, appears to have a role in chronic inflammatory diseases such as rheumatoid arthritis.19 There is a wide range of types of disc degeneration, from those triggered by trauma and infection to those progressing chronically with age‐related changes.