TREM2 and Alzheimer disease: To determine whether the changes in plaque structure observed in AD mice with the Trem2 R47H variant similarly affected neuritic dystrophy, we next analyzed plaque-associated N-terminal APP (n-APP), which is elevated in dystrophic neurites due to impaired anterograde transport, and ubiquitin, which is increased in response to cellular stress and protein dyshomeostasis.