Prion diseases, such as bovine spongiform encephalopathy (BSE), chronic wasting disease (CWD) in cervids, and Creutzfeldt-Jakob disease (CJD) in humans, are a family of fatal neurodegenerative diseases caused by the conversion of the cellular prion protein (PrPC) to the abnormally folded isoform (PrPSc)1–4. This evidence concerns the gene PRNP and prion disease.