TREM2 and Alzheimer disease: Except for the highly expressed marker genes, genes significantly upregulated were also found in specific microglial states, such as AD risk genes (Supplementary Table 6) (Ctsb, Ctsd, Trem2, and Tyrobp) are enriched in the activated response microglia (ARM), which was identified main activated microglia states by Sala Frigerio et al.