NOS3 and pulmonary arterial hypertension: ELA transfection significantly reduces right ventricular systolic blood pressure and N-terminal pro-brain natriuretic peptide (NT-proBNP), upregulates the expression of pathways such as Krüppel-like factor 2/endothelial nitric oxide synthase (KLF2/eNOS), and inhibits pulmonary arteriole remodeling by weakening endothelial interstitial transformation and media thickening in PAH rats (58).