Human LRRK2 expression in LRRK2/TauP301L mice did not affect human tau levels in the normal (soluble) fraction (Fig. 4c, d) when compared to TauP301L mice alone, ensuring that any effects on tauopathy in the LRRK2/TauP301L mice would not be due to expression artifact. Here, LRRK2 is linked to tauopathy.