Regarding immune cell infiltration, compared to control groups, the violin plot demonstrated that AD patients had a higher level of activated CD4 memory T cells (P = 0.001), M2 macrophages (P = 0.004), activated mast cells (P < 0.001), and neutrophils (P = 0.005) and a lower level of naive CD4 T cells (P < 0.001), activated NK cells (P < 0.001), monocytes (P < 0.001) and resting dendritic cells (P = 0.043) (Fig. 5B). This evidence concerns the gene CD4 and Alzheimer disease.