GFP-expressing cells were observed adjacent to amyloid plaques (stained with X-34) in all aged APP/PS1 mice (>10 months of age; Figure 3B and Supplemental Table 1), but they were not detected in WT brain parenchyma (Figure 3A) or in 6-month old APP/PS1 mice (Supplemental Table 1) at a stage prior to development of significant plaque pathology (27). Here, APP is linked to amyloidosis.