The complete series of low plaque non-demented (n = 16), high plaque non-demented (n = 15) and AD cases (n = 14) were stained for PGRN in combination with 6E10, an antibody that detected Aβ, and PGRN in combination with CD45, a marker to identify microglia. This evidence concerns the gene PTPRC and Alzheimer disease.