PON1 is synthesized primarily in the liver, and a portion is secreted into the plasma, where it is associated with high density lipoproteins (HDL). PON1 hydrolyzes the active metabolites of several other organophosphorus insecticides, as well as nerve agents such as sarin, soman and VX (lethal nerve agent). The PON1 polymorphism may be responsible for neurodegeneration and is considered to be an independent risk factor for Parkinson’s disease.