In humans, the most common TSE is Creutzfeldt–Jakob disease (CJD), which can arise sporadically (denoted sCJD), iatrogenically through transmission of PrPSc from contaminated surgical equipment or dura mater grafts, or genetically due to mutations in the Prnp gene, which encodes PrP [8]. Here, PRNP is linked to human prion disease.