Lymphatic endothelial growth factors and vascular endothelial growth factor receptor 3 (VEGFR3) generated by TAMs promote lymphangiogenesis, release the epidermal growth factor (EGF) which can interact with colony stimulating factor 1 (CSF-1) secreted by tumor cells, and degrade proteins in the ECM through proteases such as MMP-2 and MMP-9, all of which are beneficial to facilitate the invasion and metastasis of tumors [103, 104]. Here, MMP9 is linked to neoplasm.