To further investigate the effects of glycosylation mediated by mannose in the pathogenesis of AD, Kifunensine (inhibitor of α‐mannosidase I) was used to block the N‐glycosylation synthesis (Figure 6A).[35] We found that Kifunensine (Kif) significantly blocks the glycosylation modification of BACE1 and Nicastrin (evidenced by a shift in the bands) and decreases their protein levels in CHO‐APP cells (Figure 6B,C). The gene discussed is BACE1; the disease is Alzheimer disease.