Despite previous research showing that Npc genes are not associated with Alzheimer’s disease (AD) [88], efforts to target cholesterol trafficking as anti-cancer therapy will have to consider possible wide-spread effects not only in ISCs, but also in the brain, since cholesterol metabolism deregulation and cholesterol penetration through a disrupted blood–brain barrier has been suggested to contribute to AD [89,90], a mechanism which could hypothetically be implicated in Parkinson’s disease as well [90,91]. This evidence concerns the gene NPC1 and cancer.