We recently described a model of seeded PrP proteinopathy following the inoculation of rec.Wt-PrP and rec.101L-PrP amyloid fibrils into knock-in mice homozygous for the proline to leucine mutation at PrP codon 101 (101LL) [8]. The gene discussed is PRNP; the disease is familial pityriasis rubra pilaris.