We performed immune infiltration analysis on these eight key genes, and the analysis results revealed that seven genes (SNRPG, UQCRB, PSMA3, DPM1, MED6, RPL36AL, RPS27A) had significantly lower levels of activated regulatory T cells (Tregs), CD4 naïve cells, memory B cells, resting NK cells, neutrophils, macrophages M0, and mast cells than ARHGAP4 in AD patients (p<0.01). The gene discussed is CD4; the disease is Alzheimer disease.