A set of nine brains and 21 skeletal muscle specimens from domestic pigs experimentally challenged with C-type BSE (20), sheep (ARQ homozygous) scrapie (56), and white-tailed deer (PrP 96 G/G) CWD (61) prions was analyzed (Fig. 1 and Materials and Methods). The gene discussed is PRNP; the disease is scrapie.