TREM2 and Alzheimer disease: Interestingly, TREM2(+/–) deficiency is associated with increased Aβ plaques and phosphotau-positive dystrophic neurites compared to complete knock-out of TREM2(–/–) in AD mice, demonstrating a complex relationship between microgliosis and plaque-associated neurofibrillary pathology (Delizannis et al., 2021).