To gain further insight into LRRK2 phosphorylation we have studied adult, aged and α-synuclein fibril-inoculated Lrrk2 S910A/S935A double knockin mice, to determine how the loss of Lrrk2 phosphorylation impacts on PD-like nigrostriatal pathology under these different conditions. Here, LRRK2 is linked to Parkinson disease.