GFER and Alexander disease: In addition, using double label immunofluorescence, we found the expression of phospho-Hpo and phospho-Wts, the active forms of these kinases, were reduced in the cytosol of glial cells (wrapper marks glial membranes and Repo marks the nuclei of glial cells) in Alexander disease model flies (Supplementary Fig. 3d-g, GFAPR79H, arrows) compared to age-matched control flies (Supplementary Fig. 3d-g, Ctrl, arrowheads).