In addition, as compared with the normal group, the total IgE level in AD mice increased by 2.32 times, while EGCG at a dose of 100 mg/kg significantly reduced the total serum IgE level from (10.46 ± 0.97) to (8.33 ± 0.74) μg/mL (Figure 3C, p < 0.05). This evidence concerns the gene IGHE and Alzheimer disease.