TUSC3, SNCA, SLC18A2, SCN3A, PTPRN, PBX1, ORC5, OPA1, LRRN3, CHGB, CACNB2 and ADAM23 were found to be downregulated in both the SN region and blood samples of PD patients. The gene discussed is LRRN3; the disease is Parkinson disease.