PDE5A and pulmonary arterial hypertension: Despite recent advancements in prognosis for some patients through targeted therapies (e.g., endothelin receptor antagonists, PDE5 inhibitors), the pathogenesis of PAH remains insufficiently understood, and early diagnosis and precise treatment strategies are lacking.[1] Accumulating evidence suggests that PAH is not only linked to vascular contractility abnormalities but also strongly associated with metabolic reprogramming, epigenetic regulation, and posttranslational modifications (PTMs) of proteins.[2–4]