“…Matrix metalloproteinases (MMPs) are enzymes known to degrade the ECM, and 23 types have been reported in humans [46]. Of these enzymes, MMP-1, -2, -3, -8, -9, -13, and -14 have been reported to be involved in promoting the migration and infiltration of osteosarcoma cells [47,48,49,50,51,52,53,54]. The substrate of MMP-1, -8, and -13 is type I collagen, and that of MMP-2, -3, -9, and -13 is type IV collagen, and furthermore, laminin is another substrate of MMP-2, -3, and -14.…”