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. This evidence concerns the gene NPC1 and Dravet syndrome.