We addressed this question in the 5xFAD transgenic AD model and observed a significant increase in both cortical and hippocampal GFAP concentrations in transgenic mice at 7 months of age compared to wild-type mice, a time point preceding the onset of spatial memory impairment that is typically observed at 9 months in this AD model (42). The gene discussed is GFAP; the disease is Alzheimer disease.