APP and amyloidosis: In APP‐PS1 mice, which show widespread amyloid plaques in the brain by 3–4 months of age (Radde et al, 2006), TREM2 knockdown was associated with higher amyloid plaque burden at 8 months (Jay et al, 2017) and 12 months (Sheng et al, 2019), i.e., when amyloid plaque deposition is already quite expanded but still increasing.