Leucine-rich repeat kinase 2 (LRRK2) first came to prominent attention in 2004, when linkage analysis and positional cloning uncovered LRRK2 mutations associating with autosomal dominantly inherited Parkinson’s disease (PD) (Paisan-Ruiz et al., 2004; Zimprich et al., 2004). The gene discussed is LRRK2; the disease is Parkinson disease.