LRRK2 and Parkinson disease: While the majority of PD cases are sporadic, approximately 10% of cases (Verstraeten et al., 2015) are explained by the dysregulation of proteins including PARKIN (PARK2) (Kitada et al., 1998, Mizuno et al., 2008), PTEN-induced putative kinase 1 (PINK1 or PARK6) (Valente et al., 2004), α-synuclein (PARK1/4) (Polymeropoulos et al., 1997), and leucine-rich repeat serine/threonine protein kinase 2 (LRRK2 or PARK8) (Funayama et al., 2002, Zimprich et al., 2004).