Among the 94 neurologically affected mice, 29 mice (all PrPres positive) presented a classical vCJD profile: they exhibited significant neuronal lesions (mainly neuronal vacuolation), cerebral and spinal sponjpgorm change (Fig. 2a, b) associated with the accumulation of abnormal PrP (PrPd) in both brain and spinal cord (Fig. 2c) and in their spleen (Supplementary Fig. 1). This evidence concerns the gene PRNP and variant Creutzfeldt-Jakob disease.