We also see that many individual GWAS-identified risk genes for AD, PD, MS, and ALS (Supplementary Fig. 12a through d, respectively) are expressed in most of the clusters and are not enriched in any particular microglial subset; however, microglial cells belonging to cluster 4 and 7 do have a higher expression of some of the AD susceptibility genes, such as APOE and TREM2 respectively (Supplementary Fig. 12a). Here, TREM2 is linked to Alzheimer disease.