LRPAP1 and early-onset autosomal dominant Alzheimer disease: Alzheimer's disease cases had significantly lower RAP levels compared to controls (p < .0001, Figure 1a) although no significant differences in the brain tissue levels of LRP1 (p = .45, Figure 1c) or NeuN (p = .59, Figure 1b) were seen between groups (Figure 1, Table 2).