AQP12A is an aquaporin water channel protein with tissue-restricted expression in the human pancreas. The protein is selectively localized to pancreatic acinar cells 1, where it is proposed to function in intracellular water homeostasis [UniProt annotation]. Unlike most aquaporins that localize to the plasma membrane, AQP12A appears to be targeted to intracellular organelles 1, suggesting a specialized role in digestive enzyme secretion through maturation and exocytosis of secretory granules rather than transcellular water transport 1. Structurally, AQP12A is among the most divergent aquaporins, featuring modified NPA signature motifs and unique pore-lining residues that distinguish its channel properties from classical water-transporting aquaporins 2. Clinically, genetic analysis of AQP12A in 292 German patients with non-alcoholic chr2 pancreatitis revealed no significant association between AQP12A variants and disease susceptibility, though a common nonsense variant in the paralogous AQP12B suggests functional redundancy or dispensability within the AQP12 subfamily 3. AQP12A represents a pancreas-enriched protein 4 whose precise molecular function remains incompletely characterized but likely involves intracellular secretory processes rather than classical osmotic water transport.