PRNP and Creutzfeldt Jacob disease: To assess the susceptibility of these novel transgenic lines to prion infection, we first inoculated them with well characterised isolates of classical CJD with proven transmissibility to mice expressing wild-type human PrP [35], [37], [39], [40] although recognising that the presence of the A117V mutation may introduce a transmission barrier to prions generated from wild-type PrP.