This is based on the following findings: the pathogenic, PD causing VPS35[D620N] knock-in mutation stimulates LRRK2-mediated phosphorylation of at least 3 Rab proteins (Rab8A, Rab10, and Rab12) in MEFs (Figure 2) as well as enhancing Rab10 phosphorylation in mouse tissues that express LRRK2 (the lung, kidney, spleen, and brain) (Figure 4). The gene discussed is RAB8A; the disease is Parkinson disease.