The ε 4 genotype of ApoE protein regulates α-Syn pathology in humans (Davis et al., 2020) and is linked to a heightened risk of dementia among patients with PD, while ApoE ε 2 may prevent the aggregation of α-syn and its link with neurodegenerative processes in synucleinopathies (Bras et al., 2014; Mata et al., 2014). This evidence concerns the gene APOE and dementia.