This subset of microglia displays unique transcriptional features, expressing typical microglial protein markers, such as Iba1 and Hexb but with a decrease in signature microglia homeostatic genes, such as Cx3cr1 and P2ry12/13, and upregulation of genes involved in lipid metabolism and phagocytic pathways, such as Apoe, Lpl, CD9, Cst7, and Trem2. Furthermore, DAM can play dual roles in Alzheimer’s disease (AD) pathogenesis, involving the production and release of pro-inflammatory factors including cytokines and toxic factors as well as neuroprotective, anti-inflammatory functions (6). The gene discussed is CD9; the disease is Alzheimer disease.