LRRK2 and Parkinson disease: The finding that neurons can be generated in the adult brain11, together with the observation that Parkinson’s disease genes, including SNCA, PINK1 and LRRK2, are implicated in the regulation of neurogenesis12–19, raises the possibility that reduced de novo neurogenesis from neural stem/progenitor cells in adult life could contribute to neuronal decline in Parkinson’s disease.