Studies show that the process of VEGF-C (tumor overexpressed ligand)/VEGFR-3 (receptor for VEGF-C expressed on TAMs) promotes lymphangiogenesis by directly affecting the activity of lymphatic endothelial cells (lymphatic endothelial cells) or indirectly increasing the secretion of ductal proteins to promote lymphangiogenesis, which supports the hypothesis that lymphangiogenesis is closely related to TAMs and also further suggests that TAMs play an important role in tumor invasion and metastasis (78, 79). This evidence concerns the gene FLT4 and neoplasm.