Especially, in immunoreactions, genes such as: AMIGO2, BTG1, CD24, CD44, CDC42EP4, IFITM1, IFITM2, IRF7, IFI44L, IL4R, IRAK1 and NFKBIA were found upregulated in severe AD; and CD22 / MAG were downregulated. The gene discussed is BTG1; the disease is Alzheimer disease.