When the genes downregulated in the BAC-TRAP dataset were compared to genes implicated by PD GWAS and QTL (see methods), 15 genes were found; four neuron-enriched genes were chosen for confirmation; Dalrd3, Kcns3, Hdac5, and Dgkq were reduced with knockdown and not increased with overexpression (Fig. 6i). This evidence concerns the gene HDAC5 and Parkinson disease.