Because the identified biomarkers were associated with M1 macrophages, we further quantified the M1/M M2 macrophage proportion in PAH tissues (Supplementary Figure S5A) and analyzed the correlations between the five genes (RRAS, BECN1, MFN1, HIF1A and TAX1BP1) and canonical M1/M2 surface markers or functional molecules (Supplementary Figure S5B–D). Here, HIF1A is linked to pulmonary arterial hypertension.