Impairment of ceruloplasmin ferroxidase activity is associated with severe intraneuronal copper deficiency in the PD SNc (Davies et al., 2014; Genoud et al., 2017), which likely favors copper delivery to cuproproteins with high copper‐binding affinities (SOD1, cytochrome c oxidase) at the expense of ceruloplasmin. The gene discussed is SOD1; the disease is Parkinson disease.