PRNP and Alzheimer disease: On the one hand, it has been demonstrated that (i) genetic deletion of PrNP (the gene encoding for PrPC) reversed hippocampal synapse loss and completely rescued pre-existing behavioral deficits in APPswe/PS1ΔE9 mice transgenic model of AD [13]; (ii) the binding of a specific antibody, AZ59, to PrPC blocks the binding of ß-amyloid to PrPC protein.