Significant roles of metal ions have also been observed in the course of neurodegenerative diseases such as Alzheimer’s, Parkinson’s, Huntington’s diseases or amyotrophic lateral sclerosis (Gaeta and Hider 2005; Barnham and Bush 2014), where they influenced the efficiency of aggregation of proteins such as β-amyloid and hyperphosphorylated tau protein or modulation of the level of reactive oxygen species. The gene discussed is MAPT; the disease is Parkinson disease.