FLT4 and neoplasm: Angiogenesis is mediated by vascular endothelial growth factor (VEGF) and acts as an important role in the process of tumor growth and metastasis.[12] Vascular endothelial growth factor receptor (VEGFR) family proteins are membrane receptor tyrosine kinases, including VEGFR-1, VEGFR-2, and VEGFR-3.[13] VEGF-2 is closely associated with the occurrence of tumor.