Gst is a large family involved in detoxification and antioxidation; herein, gst-4 (human ortholog of hematopoietic prostaglandin D synthase (HPGDS)) is widely accepted as an antioxidative marker and plays a neuroprotective role in C. elegans of PD [56, 57]. The gene discussed is HPGDS; the disease is Parkinson disease.