TREM2 and Alzheimer disease: These cells downregulated genes associated with homeostatic microglia (TMEM119, AND P2RY12, and CX3CR1) and upregulated different genes (CLEC7A, ITGAX, CD9, and CD63), including those linked to AD risk factors (TREM2, DAP12, APOE, CTSD, and LPL).