When evaluating the disease, IgG-γ, IgM-μ, IgG2, IgG4, IGHG2, IGHG4, IgG2 ng/mL, IgG4 ng/mL, and IgM ng/mL were demonstrated to be significantly elevated in AD (n = 16) compared to Normal (n = 9) (p = 0.023, p = 0.005, p = 0.008, p = 0.004, p = 0.002, p = 0.003, p = 0.02, p = 0.027, and p = 0.005, respectively). This evidence concerns the gene IGHG4 and Alzheimer disease.