However, another hypothesis explaining Aβ accumulation in AD astrocytes is that it could be the result of impaired lysosomal function [64,70]; in support of this, the stimulation of lysosomal biogenesis in astrocytes has been shown to reduce amyloid plaque load in the hippocampus of APP/PS1 transgenic mice and in vitro [71,72]. The gene discussed is APP; the disease is Alzheimer disease.