PRNP and Creutzfeldt Jacob disease: The idea that pituitary-derived human growth hormone recipients might have been exposed to pathological proteins from Alzheimer’s or Parkinson’s disease brains (in addition to prion protein from CJD brain) was raised by Irwin et al. [41], demonstrated by Jaunmuktane et al. [42] and confirmed and extended by us [70] and others [9, 17].