An illustrative example of GFAP accumulation and aggregation is given by the Alexander disease, where mutations in this protein are linked to the formation of Rosenthal fibers (RFs) [109,110], which are dense intracellular inclusions that include a multitude of proteins ranging from cytoskeletal scaffold proteins, to intermediate filaments, to small heat shock proteins, and to ubiquitin [111]. Here, GFAP is linked to Alexander disease.