Genetic and clinical evidence suggest a pathogenic role for leucine-rich repeat kinase 2 (LRRK2) in both sporadic and familial Parkinson's disease (PD) (Healy et al., 2008; Nalls et al., 2014; Paisan-Ruiz et al., 2004; Zimprich et al., 2004). Here, LRRK2 is linked to Parkinson disease.