MMP9 and intervertebral disk degenerative disorder: In our preclinical study, we found that antagomir-338-3p (an miR-338-3p inhibitor) protected intervertebral discs against the typical pathological pattern of IDD by inhibiting the apoptosis of NP cells, enhancing the expression of extracellular matrix proteins (Col II and Aggrecan) and inhibiting the expression of extracellular matrix-degrading enzymes (MMP9 and ADAMTS4).