We then performed extraction and concentration of Aβ from the AD brain homogenate as detailed in Supplementary Methods and showed that the treatment of AD brain-derived Aβ resulted in approximately 10% synapse loss in the MAPT+/+ neurons but not in the MAPT+/− and MAPT−/− neurons (Supplementary Fig. 7D; Exon 4). The gene discussed is MAPT; the disease is Alzheimer disease.