APP/Aβ- (Figure 2A) and Aβ42-ir (Figure 2B) plaque loads were significantly increased in DS compared to HC cases (Kruskal–Wallis, p < 0.01), while DS Aβ42-ir plaque load was greater than AD (Kruskal–Wallis, p = 0.01). Here, APP is linked to Alzheimer disease.