APOE and Parkinson disease: As an indirect effect of A1, iron-induced oxidation (B1 in Table 1) has an impact on the pathways related to lipid metabolism in AD and PD, regulated by the Apolipoprotein, in particular ApoE, which is known to be one of the most validated risk markers for sporadic AD, with ApoE4 representing the strongest genetic risk factor for the development of late-onset AD [41].