These diseases, which include CWD, scrapie in sheep and goats, bovine spongiform encephalopathy (BSE) in cattle, and Creutzfeldt-Jakob disease (CJD) in humans, are caused by misfolded, infectious conformations (PrPSc) of a host encoded (PRNP gene) cellular prion protein (PrPC; Prusiner 1982). This evidence concerns the gene PRNP and scrapie.