AQP4 and Alzheimer disease: The same meaning keywords were merged: (1) AQP4, AQP-4, aquaporin-4 and aquaporin 4; (2) Alzheimers’-disease, Alzheimers-disease, Alzheimer-disease, and Alzheimer disease; (3) blood–brain barrier, blood–brain-barrier, and blood brain barrier; (4) white-matter hyperintensities and white matter hyperintensities.