GFAP and Huntington disease: Double labeling with GFAP and GSK-3β revealed GSK-3β expression in a restricted number of astrocytes in CT (Figures 2i and j), whereas its expression was detected in a much greater number of GFAP+ astrocytes in HD (Figure 2k), showing a significantly increased (P<0.01) GFAP-IR as well as cell density (P<0.01) in the dentate gyrus (DG) as compared with CT (Supplementary Figures S3B–D).