To validate this, immunohistochemistry (IHC) staining for the endothelial marker CD31 was performed on each AML and the percentage of endothelial cells was calculated by digital analysis, revealing a strong correlation with the percentage predicted by scRNA-Seq (Fig. 4c) and a higher percentage of endothelial cells in SLS-dominant tumors (Fig. 4d, Supplementary Fig. 7a). This evidence concerns the gene PECAM1 and acute myeloid leukemia.