PRNP and Alzheimer disease: Having in mind that PrPC interaction with Aβ peptides relays Aβ toxicity [33, 44] and amplifies Aβ production in AD [9], nanoparticles, by stimulating the production of Aβ40/42 peptides, might start a vicious circle of Aβ production/amplification, thus contributing to the onset of idiopathic Alzheimer’s disease.