Astrocytic GFAP expression is associated with aging and AD (Middeldorp & Hol, 2011); dominant GFAP mutations in Alexander disease cause protein aggregates that contain GFAP, vimentin, plectin, ubiquitin, and small chaperones such as α‐crystallin (Hagemann et al., 2009). This evidence concerns the gene PLEC and Alzheimer disease.