MMP9 and neoplasm: Specifically, the ability of MMP-9 to proteolyze type IV collagen in the basal lamina of tumors can alter the structure of the ECM and ease the invasion process.28, 29Furthermore, MMP-9 can degrade the adhesive proteins on the surface of malignant cells responsible for cell-to-cell adhesions as well as the proteins which adhere cells to the ECM.18, 30, 31Thus, cells can be released more easily from the tumor tissue and metastasize.