MMP9 and neoplasm: These events involve MMPs (e.g., MMP-2 and MMP-9), cathepsin, fiber protease release, type IV collagen, LN, gelatin, fiber connection proteins, other components outside the matrix involved in synthesis and degradation, collagen enzyme inhibitors (e.g., tissue inhibitors of metalloproteinase 1 and 2), adhesion molecules, and tumor cells that release fibroblast growth factor, vascular endothelial growth factor, and angiogenesis inhibitors (20).