For example, Slc1a2, Prdm16, Kank1 and Ddah1 were target genes of Dbx2, the high expression of Slc1a2 was found to reduce the risk for PD in a Chinese cohort [19] and the other genes are associated with cognitive function [20], autism spectrum disorder [21] and depression-like behavior [22], respectively. Here, DDAH1 is linked to Parkinson disease.