The TREM2 module shares a significant number of genes with another microglial module, and is enriched for genes of the innate immune system and adaptive immune system, such as the microglial-specific genes CX3CR1, ITGAM, AIF1, FCER1G, and CD68. The authors then looked at a number of other genes that have previously been associated with AD through additional studies, including GWAS. Here, TREM2 is linked to Alzheimer disease.