AQP9 and neoplasm: Recently, we assessed the expression of tumor-associated AQPs (AQP1, AQP3, AQP5, and AQP9) in the same pancreatic cancer cohort, revealing AQP1 downregulation in tumor tissues, and AQP3 upregulation in low-invasiveness grade tumors compared to high invasiveness grade pancreatic tumors [41].