PRNP and prion disease: This finding is reminiscent of previous reports that GSS patients’ brain homogenates containing only PrP amyloid fibrils, brain homogenates from diseased transgenic mice overexpressing P101L PrP, or synthetically generated rPrP amyloid fibrils are able to seed PrP amyloid plaque formation, but completely fail to cause any pathological changes of prion disease in P101L knock-in mice[38–40].