TREMendous 2 Be Social

TREM2 is known for its role in microglial phagocytosis and in neurodegenerative diseases. In this issue of Immunity , Filipello et al. (2018) show that microglial TREM2 is required for synaptic pruning in early development. TREM2-deficient mice show altered social behavior in adulthood, linking TREM2 to neurodevelopmental disease.