PECAM1 and intervertebral disk degenerative disorder: Endothelial cells, osteoclasts, and BMDMs are involved in the process of CEP remodeling and disc degeneration in both animal models and IDD patients.34,35,66,74–76 Similarly, we observed positive staining of CD31, TRAP, and F4/80 in human CEP specimens (Fig. S5A–C), laying a solid foundation for the conclusion of this study.