GJA1 and Alzheimer disease: Mathys et al. reported that, in contrast to neurons and similarly to the other glial cells, astrocytes present a general upregulation of expression markers, with GFAP, SYTL4, MT1E, ZFP36L1, MT2A, and GJA1 standing out, but a downregulation of APOE. Among astrocytes, they found a specific subpopulation which was differentially associated to AD and characterized by the expression of GLUL and of the AD risk factor CLU [103].