TREM2 and Alzheimer disease: This has led to the idea that R47H is a loss‐of‐function mutation, which in turn suggests that wild‐type TREM2 protects against AD, probably by increasing microglial phagocytosis of Aβ, and thereby removing neurotoxic Aβ oligomers and compacting amyloid plaques (Condello et al., 2015; Gratuze et al., 2018; Kulkarni et al., 2021; Olufunmilayo & Holsinger, 2022; Yuan et al., 2016).