The expression levels of genes that have been confirmed to be associated with the development of IDD were assessed in different clusters, of which APOE, ATXN7, LMNA, GDF5, and HGD were overexpressed in MAPK cluster A and gene cluster A, whereas SNRNP200, OFD1, and NT5E were downregulated in MAPK cluster A and gene cluster A (Figure 6C). The gene discussed is APOE; the disease is intervertebral disk degenerative disorder.