IGF1 and intervertebral disk degenerative disorder: Studies have reported that the expressions of IGF are significantly abnormal in degenerative IVD tissues and cells, and it is involved in multiple pathological processes of disc degeneration by participating in cell proliferation, programmed death, degeneration and synthesis of ECM (Tao et al., 2015; Chen et al., 2020; Zhao et al., 2020).