In light of the key role of SIRPα in mediating the phagocytosis of apoptotic cells and its possible involvement in the clearance of amyloid-β plaques in Alzheimer’s disease, in the present study we set out to investigate the possible involvement of SIRPα in prion pathogenesis in vivo. The gene discussed is SIRPA; the disease is early-onset autosomal dominant Alzheimer disease.