The latest research also found that the age-related change in AQP4 polarity distribution (change in AQP4 localization around blood vessels) is accompanied by an increased deposition of Aβ, suggesting that the change in AQP4 polarity distribution weakens the glial–lymphatic function of AD patients and increases Aβ deposition, thus promoting protein aggregation and neurodegeneration (Zeppenfeld et al., 2017; Kitchen et al., 2020). Here, AQP4 is linked to Alzheimer disease.