Ajsuvakova et al. (2020) reported that the copper to ceruloplasmin ratio was reduced in PD patients indicating that copper ions were not bound to ceruloplasmin as expected, but on the contrary copper was either free or bound to other low molecular weight species such as amino acids. Free Cu contributes to oxidative stress and binds to α-synuclein leading to neuronal degeneration. Increased concentrations of copper have been observed in the cerebrospinal fluid of Parkinson’s patients (Pall et al., 1987; Davies et al., 2016). This evidence concerns the gene CP and Parkinson disease.