GFAP and Alzheimer disease: AD7c-NTP was associated with AD neurodegeneration, and the silencing was mediated, in part, by MeCP2 phosphorylation at serine 421 (S421) coupled to DNA demethylation in the Gfap, Nestin and DCX promoters, preventing MeCP2 from binding to its cellular target, and thereby decreasing transcriptional repression to induce gene expression.