HPGD and Parkinson disease: The same genes linked to the pyruvate dehydrogenase activity were also found to be downregulated in PD brains compared to controls, as well as other genes linked to lipid metabolism, such as DLD, ALDH1A, IDI1, AUH, HMGCL, RDH11, HMGCS1, SERINC1, ACADM, ACAT2, YWHAH, GSTZ1, NSDHL, HSD17B10, MIF, ELOVL5, CPT1A, ACSL4, HPGD, and IDH1.