MMP9 and neoplasm: In this procession, matrix metalloproteinases(MMPs), particularly MMP9, which is delivered into the tumor microenvironment by M2 macrophages, favoring tumor stromal angiogenesis [12], and other study also showed M2 macrophages produces many proangiogenic factors and expresses high levels of MMP9, which promote cancer cell invasion, metastasis and angiogenesis [13].