GAD1 and autism: Fifth, we explored SLC39A8 expression in single cells from the human brain (CoDEx Viewer: http://solo.bmap.ucla.edu/shiny/webapp/, UCSC cell browser: https://cells.ucsc.edu/?ds=autism, and Transcriptomics Explorer of Allen brain map: https://celltypes.brain-map.org/rnaseq/human_ctx_smart-seq?selectedVisualization=Heatmap&colorByFeature=Cell+Type&colorByFeatureValue=GAD1), and found that SLC39A8 is not widely expressed in different cell types of the human brain (Supplementary Figures 8, 9).