Prominently, in rodent models of neurodegenerative diseases including the Alzheimer’s disease (AD) and Amyotrophic lateral sclerosis (ALS), microglia display a stereotypic disease-associated microglia (DAM) phenotype (17), which appears to be an inflammatory state driven by a TREM2-dependent pathway (18). Here, TREM2 is linked to amyotrophic lateral sclerosis.