PRNP and variant Creutzfeldt-Jakob disease: Affected Tg27 mice propagated PrPSc that was closely similar to type 4 PrPSc present in the vCJD inoculum (Fig. 1d, lanes 1 and 3) and distinct from type 5 PrPSc seen in vCJD-inoculated Tg152 mice expressing human PrP 129V (Hill et al., 1997; Wadsworth et al., 2004) (Fig. 1d, lane 2).