Furthermore, a neo-epitope antiserum specific to N-GFAP reveals the presence of the caspase-cleaved GFAP fragment in cells expressing disease-causing mutant GFAP and in two types of AxD models that have previously been shown to have varying levels of GFAP accumulation in different regions of the CNS (central nervous system) (Messing et al., 1998; Hagemann et al., 2006). Here, GFAP is linked to Alexander disease.