GRIA2 and amyotrophic lateral sclerosis: The upregulation of GluA1 mRNA, which reduces the proportion of the GluA2 subunit among the four subunits, is associated with excitotoxicity in the spinal cord and iPSC-derived motor neurons of patients with C9orf72 ALS [109] and FUS knockdown mice [110,111,112,113].