DHFR and pulmonary arterial hypertension: As shown in Figure 6A–6D, though A-SeQDs prevented the formation of PAH in WT mice injected with monocrotaline, it did not reduce RVSP, RV/(LV+S), the thickness and collagen depositions in pulmonary arterial walls in DHFR-/- mice, suggesting that these beneficial effects of A-SeQDs on PAH depend on DHFR.