GFAP and Alexander disease: To extend these previous reports to the protein level in whole brain, LC-MS/MS-based proteomics was performed on a severe mouse model of AxD (referred to hereafter as GFAPTg;Gfap+/R236H), which harbors a disease-causing heterozygous point mutation at R236H in murine Gfap as well as elevated levels of GFAP due to a human GFAP transgene expressed in astrocytes (18).