NOS3 and acquired polycythemia vera: In patients with PV, VEGF upregulated the expression of key angiogenic mediators, including endothelial nitric oxide synthase (eNOS) and hypoxia-inducible factor-1α (HIF-1α), an effect potentiated by IL-6 and amplified under JAK1/2 inhibition (e.g., Ruxolitinib).