The proportion of M2 macrophages decreased with the progression of IDD followed by an increase in the proportion of M1 macrophages, indicating the crucial role of macrophage polarization in amplifying the inflammatory cascade during the process of IDD.45 A novel cell subtype, granulocytic myeloid-derived suppressor cells, was enriched at the middle stage and contributed to delaying NP cell degeneration by suppressing IL1-β and IL-2, which might be a potential treatment target for IDD46 (Fig. 3). This evidence concerns the gene IL2 and intervertebral disk degenerative disorder.