PRNP and fatal familial insomnia: Human prion diseases include Creutzfeldt-Jakob disease (CJD), Gerstmann-Straussler-Scheinker syndrome (GSS), kuru, fatal familial insomnia (FFI) (for review, see [1]), PrP cerebral amyloid angiopathy [2] and variably protease-sensitive prionopathy [1, 3].