To check if GFP aggregations in zebrafish embryos are akin to GFAP aggregations in AxD patients, we performed transmission electron microscopy (TEM) on zebrafish embryos microinjected with expression plasmids encoding WT or p.Arg79Cys allele of GFAP, and indeed found electron dense inclusions in the cells of both groups of embryos (Fig. 4a-c), which is reminiscent of TEM findings of RFs in the astrocytes of the AxD brain [35]. Here, GFAP is linked to Alexander disease.