These so-called disease-associated microglia (DAM) are typified by a downregulation of genes indicative of microglial homeostasis for example Tmem119, P2ry12, and Cx3cr1, and an upregulation of genes recognized as risk factors in AD like Apoe, Tyrobp, Trem2, Ctsd, and lpl (Keren-Shaul et al., 2017). Here, TREM2 is linked to Alzheimer disease.