MMP13 and intervertebral disk degenerative disorder: A study reported that in combination with cartilage-derived stem cells with a molecular therapeutic (NTG-1010), when treated in a rat-tail model of degenerative disc disease, the results demonstrated robust cellularity, maintenance of disc height and size of the NP, decreased levels of matrix degrading enzymes (e.g., MMP-3 and MMP-13) and pro-inflammatory cycloxygenase-2, and that the levels of type II collagen and aggrecan are largely unregulated [51].