PRNP and X-linked retinal dysplasia: Growing evidence indicates that membrane lipid rafts are involved in the generation of Aβ and PrPsc amyloidogenic-peptides from amyloid precursor protein (APP) and cellular prion protein (PrPc), (deposition of which in brain parenchyma and vessel walls are the major pathological feature of AD and PrD, respectively), possibly through the creation of a favorable lipid environment (Figures 1 and 2) (Pani et al., 2011).