KL and Alzheimer disease: Another study highlighted that the upregulation of Klotho protein levels in the brain and serum significantly improved Aβ damage, neuronal and synaptic loss and cognitive deficits in amyloid precursor protein/presenilin mice, to the point that the authors concluded that, given the neuroprotective effects of Klotho overexpression, the latter should be further investigated as a potential therapeutic target for AD [206].