In Familial ALS, SOD-Cu(I) complexes are affected by H2O2 resulting in free radical production; in AD, the reduction of Cu(II) to Cu(I) by APP involves an electron-transfer reaction and could lead to a production of OH•, thus, copper-mediated toxicity of APP-Cu(II)/(I) complexes may contribute to neurodegeneration in AD[78]. Here, APP is linked to Alzheimer disease.