TNF and intervertebral disk degenerative disorder: Since all of these genes are involved in mitochondrial energy metabolism, it suggests that disc degeneration may be closely related to imbalance of cellular energy homeostasis,[22–25] NFU1 and NDUFA13 are both involved in mitochondrial energy metabolism pathway, NFU1 affects respiratory chain complex I function through iron-sulfur cluster (Fe-S) assembly and participates in mitochondrial redox reactions, while NDUFA13 (also known as GRIM-19) as the complex I subunit, may delay IVDD progression by regulating redox homeostasis with inhibition of inflammatory factors (e.g., IL-6, TNF-α).