GAD2 and amyotrophic lateral sclerosis: GSEA further confirmed that genes involved in glutamate uptake were significantly decreased in expression in ALS astrocytes (including GAD2, ADRA1A, CBLN1, PTPRT, CACNG3, CPLX2, NRXN1, KCND2, SHISA6, ELAVL4, GRIN1, GRIN2B; NES −2.5, P < 1 × 10−10) (Fig. 2D).