SOX9 and intervertebral disk degenerative disorder: Sox9 (SRY‐Box 9), a transcription factor that promotes the expression of chondrocyte‐specific genes including aggrecan and collagen II,42, 43 was confirmed to be the direct target of miR‐616‐5p.36 These findings suggest that upregulation of circ‐4099 in NP cells could act as an inflammation‐responsive autoprotective mechanism against IDD development via modulating the miR‐616‐5p‐Sox9 pathway.