PDPN and myeloid sarcoma: The purpose of this study was to investigate the role of lymphatic vessel endothelial hyaluronan receptor and podoplanin, which are specific to the lymphatic system, and prospero-homeobox protein-1, angiopoietin-2, vascular endothelial growth factor-D, and vascular endothelial growth factor receptor-3, which are expressed by both lymphatic endothelium and neurons in MS pathogenesis.