CX3CR1 and Alzheimer disease: Subclusters 2, 3 and 6 were enriched for expression of homeostasis genes, such as CX3CR1 and P2RY12, but also enriched for several neuron-related genes, such as GRID2, ADGRB3 and DPP10. These subclusters were also more abundant in CTR+ and AD samples than in CTR samples, and denoted as “AD2” microglia.