PRNP and Creutzfeldt Jacob disease: The reversibility of PrP detection in c-BSE and v-CJD primates induced by a denaturation step argues for an impairment of the epitope detection due to the folding state of PrPBSE/v−CJD, whereas in myelopathic primates, this phenomenon would be related to an actual absence of detectable PrP by this technique.