TREM2 and neurodegenerative disease: Indeed, mitochondrial impairment, namely energy deficiencies and aberrant ROS signaling, has been previously linked to several neurodegenerative diseases,35 most notably Parkinson’s disease36 but also AD and aging.37, 38, 39 Our current findings are the first to show these metabolic deficits in disease relevant and human TREM2 hypomorphic microglia.