Finally, while the review aimed to explore inflammatory effects in humans, there was some variation in the primary indication for PDE5 inhibitor treatment (e.g., erectile dysfunction, pulmonary hypertension, cystic fibrosis, benign prostatic hyperplasia), which introduces potential confounding factors, as the pathophysiology, inflammatory pathways, and clinical contexts differ across these conditions, making appropriate interpretation harder. The gene discussed is PDE5A; the disease is pulmonary arterial hypertension.