PRNP and infection: The different incubation times and pathology seen after scrapie infection in mice expressing anchored versus anchorless PrP might be explained by differences in various aspects of the disease process including: first, different toxicity of amyloid and non-amyloid forms of prions; second, different susceptibility of mice to prion infection or damage; third, different ability to spread the infection to CNS locations resulting in clinical disease.