The quantitative analysis of the hippocampal area immunopositive for CD68 showed that 3xTg‐AD mice injected with the old‐Tg mice brain extract had significantly less microglia positive for CD68 in the ipsilateral (57% ± 8.52% reduction) as well as in the contralateral (48% ± 13.46% reduction) side when compared with 3xTg‐AD mice treated with the human AD inocula (one‐way ANOVA, F(4, 25) = 4.219, p = 0.0096, Tukey's multiple comparisons tests, Figure S3B). The gene discussed is CD68; the disease is Alzheimer disease.