n = 163 cells (total 0.7%, 0.5% in HY, and 0.7% in MDS) were classified as ECs by expression of key markers such as Fatty Acid Binding Protein 4(FABP4), von Willebrand factor, and Platelet And Endothelial Cell Adhesion Molecule 1(PECAM1) (supplemental Table 6). This evidence concerns the gene VWF and myelodysplastic syndrome.