These included Secreted Protein Acidic And Cysteine-Rich (SPARC), Platelet And Endothelial Cell Adhesion Molecule-1 (PECAM1), Endothelin Converting Enzyme-1 (ECE1), Collagen Type XVIII Alpha-1 (COL18A1), Interleukin-5 (IL5) and Stabilin-1 (STAB1) which have been previously associated with PAH (21)(22)(23)(24) (Figure 4D, Figure S4). Here, COL18A1 is linked to pulmonary arterial hypertension.