In the CSF of PD patients, the endogenous Cp has been found deamidated at the 962NGR-motif16; while, in vitro, the 962NGR-motif underwent deamidation reaction exclusively when protein aging occurred under oxidative conditions that affect the Cp-structure and promote the exposure of the 962NGR-motif, usually hidden within the protein15. Here, CP is linked to Parkinson disease.