In prion diseases (including Creutzfeldt-Jakob disease [CJD] in humans or bovine spongiform encephalopathy [BSE] in cattle), PrP undergoes progressive, templated three-dimensional misfolding (into its pathological ‘scrapie’ isoform PrPSc) and aggregation, and its expression is thus prerequisite and driving force of these ultimately fatal neurodegenerative conditions (Bockman et al. 1985; Prusiner 1982). This evidence concerns the gene PRNP and Creutzfeldt Jacob disease.