The identification of four wheel drive (encoding Drosophila phosphatidylinositol 4-kinase beta), which catalyzes the formation of PI(4)P, is also intriguing since mutations in SYNJ1, which encodes PI(4,5)P2 phosphatase, were identified in families with early onset parkinsonism [47], [48]. This evidence concerns the gene PI4KB and Parkinsonism.