FLT4 and neoplasm: Immunofluorescent double staining was carried out on tumor tissues with VEGFR3 and LYVE-1, which are markers for LECs, and the results demonstrated that the mean micro-LVD of the tumors decreased from 13.4 ± 2.3 to 4.2 ± 1.3 as a result of treatment with fucoidan (120 mg/kg).