MMP2 and osteoporosis: Required for maintenance of bone mineral density and strength and in bone development (e.g., by affecting intramembranous and endochondral ossification); however, deregulated MMP-2 expression is observed in the settings of metabolic syndrome, osteoporosis, osteonecrosis of the jaws, ligamentum flavum degeneration in lumbar spinal canal stenosis, as well as in bone pre-metastatic niche formation.