EDN1 and angiosarcoma: Endothelium expression markers CD31, CD34, von Willebrand factor (vWF), Ulex europaeus agglutinin 1 (UEA-1), Friend leukemia integration 1 (Fli-1), endothelin-1, vascular endothelial growth factor receptor (VEGFR), and specific gene related erythroblastic transformations (ERG) can help identify angiosarcomas, each with different sensitivity and specificity [1, 6].