Matrix metalloproteinase-8（MMP-8）also known as neutrophil collagenase and CLG1，is a member of matrix metalloproteinases (MMPs) family，which degrade components of the extracellular matrix (ECM) and play essential roles in various physiological processes as well as pathological processes. MMP-8 may affect the metastatic behavior of breast cancer cells through protection against lymph node metastasis, underlining the importance of anti-target identification in drug development. MMP-8 in the tumor may have a protective effect against lymph node metastasis.