These in vitro models of tau and αSyn pathology depend on seeded formation of intraneuronal inclusions in WT neurons, and there is increasing evidence that seeded propagation of pathology through neuronal networks explains the stereotypical progression of disease observed in neurodegenerative tauopathies and α-synucleinopathies (Vaquer-Alicea and Diamond, 2019; Uemura et al., 2020). Here, MAPT is linked to synucleinopathy.