PRNP and prion disease: In prion diseases normal host-encoded cell surface-anchored prion protein (also known as PrPC or PrPsen due to its sensitivity to protease digestion) undergoes misfolding and aggregation to generate a partially protease-resistant form known as PrPres or PrPSc, which is detectable by immunoblot and is an important biochemical marker for the disease (for reviews see [1,2]).