MMP9 and neoplasm: Furthermore, a number of other proteins have been proposed to act together with podoplanin in controlling cell motility, migration and invasion, including molecules of the extracellular matrix [21], [56], [71], and matrix metalloproteinases (MMP-1, MMP-2, MMP-9, MMP-10), which are also thought to be involved in PDPN-dependent tumor progression [72], [73].