CD4 and Alzheimer disease: The distribution of 28 immune cells in the GSE37263 and GSE122063 samples is depicted in Fig. 9A. The results of the immune cell infiltration analysis demonstrated a significantly higher infiltration of monocytes, CD4+ T cells, CD8+ T cells, regulatory T cells, and natural killer (NK) cells in the brain tissues of the patients with AD than in those of the healthy controls, suggesting that these cells were essential in AD progression (Fig. 9B).