CD4 and Alzheimer disease: The results of the ssGSEA analysis indicated that compared with the control group, the abundance of activated B cell/CD4 T cell/CD8 T cell, gamma delta T cell, immature dendritic cell, natural killer cell, plasmacytoid dendritic cell, and type 17 T helper cell were significantly reduced in the AD group, while CD56dim natural killer cells, MDSC, natural killer T cells, and regulatory T cells were significantly increased in the AD samples (Figure 2E).