Among these 52 differentially expressed genes, at least 10 genes are of particular interest: the upregulation of MT1H, CXCR4, PNMT, BTG3, LRP2, AGT, S100B, MAOA and CST3 and the downregulation of CBLN1 have been observed in previous studies investigating PD or other neurological disorders. The gene discussed is PNMT; the disease is nervous system disorder.