PRNP and Creutzfeldt Jacob disease: In myelopathic primates, the lack of detection was related to a strong deficiency of full-length PrP, whereas in BSE/v-CJD primates, full-length PrP was detectable after unfolding, indicating that it was preserved from degradation by an aggregated form of PrPd that impairs recognition of certain epitopes by antibodies without a prior denaturation step as classically reported (Safar et al., 2000).