In the AD group, the levels of 55 proteins [the top nine being KVD13 (IGKV1D-13), FITM1 (FITM1), B3AT (SLC4A1), IGD, SRGN (SRGN), GTR1 (SLC2A1), STOM (STOM), K2C72 (KRT72), and EFCB6 (EFCAB6)] were upregulated, while the levels of 10 proteins were downregulated [LV151 (IGLV1-51), IGHM (IGHM), ALBU (ALB), OTUD4 (OTUD4), AT8B4 (ATP8B4), PHX2B (PHOX2B), FHR5 (CFHR5), CBLN4 (CBLN4), RBX2 (RNF7), and TEN1 (TENM1)] compared with the NC group. This evidence concerns the gene OTUD4 and Alzheimer disease.