The tumor microenvironment, particularly cancer-associated fibroblasts, can be stimulated by factors such as PDGF-D to secrete VEGF-A and VEGF-C, amplifying lymphangiogenesis and facilitating tumor cell intravasation via VEGFR2 and VEGFR3 expressed on lymphatic endothelial cells [54]. Here, FLT4 is linked to neoplasm.