MMP9 and neoplasm: MMP-9 exert these effects by cleaving a diverse group of substrates, including structural components of the extracellular matrix, growth factor binding proteins, growth factor precursors, receptor tyrosine kinases, cell-adhesion molecules and other proteinases[18].However, reports conflict as to whether increased MMP-9 expression correlates with metastasis and malignancy factors[7].MMP-9 protein is primarily expressed in the cytoplasm of both tumor and stromal cells[5].In this study, its expression in matched epithelium and lymph node tissue was associated with lymph node metastasis.