Again, the APOE-mediated regulation of microglia was found to be TREM2-dependent as the genetic targeting of TREM2 (TREM2 knockout) supressed the APOE pathway and restored the homeostatic microglia in mouse models of AD and ALS (Krasemann et al., 2017). This evidence concerns the gene TREM2 and amyotrophic lateral sclerosis.