Tg(FFI)/Prnp0/0 mice, which express mouse PrP-D177N(M128) corresponding to the human homologue of PrP-D178N(M129) in FFI in their brains 2 times higher than PrPC in WT mice, were reported to develop fatal neurological disease with motor and cognitive deficits (Table 1) [67]. Here, PRNP is linked to nervous system disorder.