MAPT and Parkinson disease: Consistent with published literature including a study of 63 de novo PD and 32 healthy control participants in PPMI, CSF α‐syn levels in PD strongly correlated with t‐tau, and to a lesser degree, p‐tau.11 In BioFIND, we also identified a modest correlation of CSF α‐syn and Aβ1‐42, which supports findings from a larger PPMI study of 660 participants (r = 0.35, P < .01).25 These findings suggest that CSF α‐syn, Aβ1‐42, and tau may interact on cellular and pathophysiological levels in PD.