In dementia common in the elderly population, such as Alzheimer’s disease, astrocytic S100A6 is homogeneously up-regulated within the white matter and in the neocortex, almost all S100A6 immunoreactivity is concentrated in astrocytes surrounding the amyloid beta deposits of senile plaques [10]. This evidence concerns the gene S100A6 and early-onset autosomal dominant Alzheimer disease.