ABCB1 and Parkinson disease: Defects in genes responsible for pesticide metabolism (PON1), transport across the blood–brain barrier (ABCB1), pesticides interfering with or depending on dopamine transporter activity (DAT/SLC6A3) and dopamine metabolism (ALDH2), impacting mitochondrial function via oxidative/nitrosative stress (NOS1) or proteasome inhibition (SKP1), and contributing to immune dysregulation (HLA-DR), may also represent additional risk factors for PD [22].