MMP2 and neoplasm: For example, the metastatic cancer cells in a number of human breast to bone metastases analyzed in our study were positive for MMP-2 and previously, the forced overexpression of MMP-2 or the endogenous tissue inhibitor of metalloproteinase-2 (TIMP-2) in cancer cells has been shown to promote or protect against tumor induced bone destruction respectively [42], [43].