TREM2 and Alzheimer disease: Despite TREM2 phagocytic role has been extensively studied in acute and chronic neurodegenerative diseases models as AD or multiple sclerosis (reviewed in Deming et al., 2018; Karanfilian et al., 2020); to the best of our knowledge, this is the first study showing a link of TREM2 with phagocytic microglia after direct or primary acute axonal injury.