On the other hand, 24-OHC has been reported to be a main player of the regulatory loop between astrocytes and neurons to maintain brain cholesterol homeostasis, and to exert several beneficial effects against AD progression, such as preventing tau hyperphosphorylation [98], suppressing Aβ production [99] in neuroblastoma cells and regulating synaptic function in rat hippocampal neurons and slices [54]. Here, MAPT is linked to Alzheimer disease.