MMP16 and neoplasm: Since MT3-MMP expression is upregulated frequently in tumors that arise in collagen-poor tissues ([28], [47]; www.oncomine.org; www.genesapiens.org), and the effects of MT1-MMP and MT3-MMP were additive promoting invasion in fibrin, MT3-MMP expression in primary tumors associated with fibrin accumulation may promote local tumor spread.