As a preliminary test to determine whether this protective effect against cognitive decline in healthy aging could be extended to the amyloid‐driven accelerated cognitive decline observed in Alzheimer's Disease mouse models, we treated a cohort of presymptomatic APP‐PS1 mice (Jankowsky et al, 2004) with PHP.GFAP‐IL2 at 2 months of age. This evidence concerns the gene APP and early-onset autosomal dominant Alzheimer disease.