MMP9 and cancer: For examples, IL-6 promotes cancer cell proliferation and recent studies showed that IL-6 also contributed to cancer cell malignant properties and effusion respectively in lung and breast cancer[43], [44]; TGF-β induces cancer cell invasion and EMT in breast cancer[27], [45]; VEGF and MMP9 are also regarded as indispensable cytokines for breast cancer cell invasion, adhesion and metastasis[32], [46].