PRNP and Alzheimer disease: In the review article “Breaking the code of amyloid-β oligomers,” available at the following link: http://www.hindawi.com/journals/ijcb/2013/950783/, S. E. Lesnè outlines the “oligomeric” view of the amyloid hypothesis in Alzheimer's disease (AD), discussing how structurally different amyloid-β (Aβ) oligomers may contribute to the pathogenesis, and the controversial role of the prion protein (PrP) in Aβ toxicity.