Greater brain water accumulation and intracranial pressure were found in AQP4 knock-out versus wild-type mice with brain tumour, brain abscess, focal cortical-freeze injury, and after infusion of normal saline directly into brain extracellular space [11, 69, 70], indicating that vasogenic edema fluid is eliminated by an AQP4-dependent route. Here, AQP4 is linked to brain neoplasm.