Since tauopathy is central in neurodegenerative processes, either in those following traumatic brain injury or in those related to PD (Delic et al. 2020), current findings support the notion that the risk of PD due to HT may result from a tau-mediated neurodegenerative mechanism, which is consistent with data showing the centrality of tau pathology in neuropsychiatric disturbances of patients with traumatic brain injury (Takahata et al. 2019). Here, MAPT is linked to hematocrit.