Prnp0/0 mice expressing mouse PrP with N-terminal residues 23-88 deleted, or Tg(PrPΔ23-88)/Prnp0/0 mice, developed prion disease after inoculation with RML scrapie prions, with accumulation of PrPScΔ23-88 in their brains [9]. The gene discussed is PRNP; the disease is prion disease.