FOXO1 and Parkinson disease: The majority of prior PD microarray studies performed in SN tissue also reported increased FOXO1 expression and enrichment of FoxO1 TFBS genes in their top results, with significant meta-analysis p-values for the two FOXO1 probes present on the Affymetrix HG-U133A chip ranging from 4.1E-3 to 3.2E-4 (Table S4).