TNF and Intervertebral disk degeneration: Based on the provided keyword co-occurrence analysis, research around 2014 primarily focused on foundational biological mechanisms, with particular emphasis on “gene expression,” “stromal cells,” and “articular cartilage.” Dysregulated expression of inflammatory cytokines—such as IL-1β, IL-6, and TNF-α—has been shown to disrupt microenvironmental homeostasis in intervertebral disc degeneration (IVDD), promoting cell senescence and apoptosis, and ultimately accelerating disease progression (40).