Compared to Aβ- CN, five plasma proteins were significantly increased in both AD and Aβ+ MCI patients, including HAGH (d = 0.79 in Aβ+ MCI; d = 1.28 in AD; q < 0.05), sirtuin-2 (SIRT2; d = 0.69 in Aβ+ MCI; d = 0.49 in AD; q < 0.05), caspase 8 (CASP8; d = 0.62 in Aβ+ MCI; d = 0.67 in AD; q < 0.01), EIF4EBP1 (d = 0.51 in Aβ+ MCI; d = 0.39 in AD; q < 0.05), and interleukin-8 (IL-8; d = 0.32 in Aβ+ MCI; d = 0.3 in AD; q < 0.05; see Fig. 1b and Table 3). This evidence concerns the gene SIRT2 and Alzheimer disease.