In patients with AD, AQP4 levels are decreased in the perivascular space, which is associated with increased NFT levels and enhanced Aβ pathology [147]; however, the protein levels of AQP4, instead of subcellular translocation, were not changed in many scenarios, including hypothermia, via transient receptor potential vanilloid 4 (TRPV4) activation [148], and osmolality changes via PKA phosphorylation in primary human cortical astrocyte [149]. Here, AQP4 is linked to Alzheimer disease.