MMP9 and metastatic malignant neoplasm in the lymph nodes: In addition to MMP-2 and MMP-9, MMP-1 has also been used as an accurate marker in a three markers scores model, including MMP-1, hepatocyte growth factor, and chemokine ligand 5, to predict axillary lymph node metastasis (LNM) positivity in breast cancer patients (65).