FLT4 and malignant glioma: Previous reports have found that proteins that are typically involved in lymphangiogenesis are expressed in glioma.28, 29 Grau et al. described a lymphatic phenotype of tumor vessels in malignant gliomas and glioblastomas as well as endothelial expression of VEGFR3 in the entire tumor vasculature with a high expression of podoplanin in cell scaffolding vessel structures.30 Jiang et al. detected the expression of lymphangiogenesis markers in primary and recurrent glioma tumors.31 At present, the source of new lymphatic vessels in tumors remains controversial.