PECAM1 and neoplasm: After gating out hematopoietic (CD45, CD14) and endothelial cells (CD31) (see Figure S4A for full gating strategy), the predominant mesenchymal cluster was single positive for CD90 (tumor, 44.2 ± 32 versus normal, 10.3 ± 8.8, n = 12) (Figure 4A).