TREM2 and dementia: Microglial TREM2 is shown to be a phagocytic receptor for apoptotic cells (Takahashi et al., 2005), and dementia‐associated mutations of TREM2 such as T66M impair phagocytic clearance of apoptotic cells in human induced pluripotent stem cell‐derived microglia (Garcia‐Reitboeck et al., 2018).