IL-17 promotes tumor proliferation, survive and metastasis by up regulating angiogenesis factors VEGF, CXCL8, MMP2 and MMP9 [37], while at the same time, it significantly suppresses apoptosis in several human breast carcinoma cell lines, such as 4T1, MDA-MB-231 cells. The gene discussed is MMP9; the disease is neoplasm.