The PARK9 gene encodes the protein ATP13A2, a transmembrane lysosomal type 5 P-type ATPase [183], which has been linked to a neurodegenerative disorder known as Kufor–Rakeb syndrome (KRS), as well as to some juvenile and early-onset forms of PD [183,184,185,186,187]. Here, ATP13A2 is linked to Parkinson disease.