Heatmap analysis demonstrated a negative correlation between RRAS and M1 macrophages, while BECN1, HIF1A, MFN1, and TAX1BP1 were positively correlated with M1 macrophages (Supplementary Figure S4B; Supplementary Table S15), this suggests that macrophages may be involved in disease progression in PAH tissues. Here, HIF1A is linked to pulmonary arterial hypertension.