TREM2 deficiency, the TREM2 R47H variant, or microglia depletion caused not only a significant increase of Aβ42 around plaques in APPPS1-21 mice but also increased seeding and spreading of human tau derived from AD patients that was directly injected into the APPPS1-21 brain [167, 168]. The gene discussed is MAPT; the disease is Alzheimer disease.