AQP1 is a transmembrane water channel protein that facilitates water transport across cell membranes, maintaining cellular water homeostasis in diverse tissues including endothelial cells, kidney, and lung 123. Beyond water transport, AQP1 exhibits permeability to small solutes including hydrogen peroxide (H2O2), glycerol, ammonia, nitric oxide, and carbon dioxide, functioning as part of a CO2 metabolon linked to anion exchange in erythrocytes 42. In endothelial cells, AQP1 plays a context-dependent role in senescence and angiogenesis: in proliferating cells, AQP1 maintains angiogenic capacity, while in senescent cells, AQP1 overexpression exacerbates H2O2-induced senescence through CaMKII-AMPK-dependent pathways 4. Clinically, AQP1 variants associate with pulmonary arterial hypertension (PAH), with rare sequence variations showing familial segregation with disease 56. Additionally, a common AQP1 promoter variant (rs2075574) correlates with reduced peritoneal ultrafiltration and increased mortality risk in peritoneal dialysis patients 7. These findings establish AQP1 as a multifunctional channel with significant roles in cardiovascular and renal pathophysiology.