Our findings suggest that while altered hippocampal NPC1 expression could be a common feature of DS and AD (Figure 2), the NPC1 immunolabeling as a disease marker of AD does not discriminate AD-pathology in patients with DS from the controls (Figure 3), suggesting that the AD continuum in the hippocampus of subjects with DS differs from NPC disease. The gene discussed is NPC1; the disease is Alzheimer disease.