MAPT and Parkinson disease: Likewise, studies on CSF t-tau and p-tau have not shown a specific profile for PD, with results of both lower and equal levels in PD compared to controls and other parkinsonian disorders (Kang et al., 2013, Parnetti et al., 2014, Parnetti et al., 2014, Hall et al., 2015, Magdalinou et al., 2015, Delgado‐Alvarado et al., 2016, Kang et al., 2016, Mollenhauer et al., 2017).