APP and Alzheimer disease: There were no differences in the levels of APP itself or its metabolites, including CTFβ, CTFα, sAPPα, BACE1, ADAM10 and PS1, between AD mice underwent splenectomy and sham control mice (p > 0.05 for all data, Figure 4e), but the Aβ monomer level in AD mice underwent splenectomy was higher than that in sham control mice (t = 2.36, p = 0.036; Figure 4e, f).