Speculations on how Tau participate in or influence the pathophysiology of PD include the following: axonal transport dysfunction may contribute to the deposition of α-Syn and disable of excretion of metabolites (Dixit et al. 2008; Y. Wang and Mandelkow 2016); Tau translocation to the excitatory synapses may be involved in excitotoxicity in PD pathology (Frandemiche et al. 2014). This evidence concerns the gene MAPT and Parkinson disease.