NPC1 and Niemann-Pick disease, type C1: Studies in which Npc1 was deleted from neurons result in similar phenotypes of mice with global deletions; however, removal of Npc1 specifically in astrocytes of mice resulted in no discernable Niemann-Pick disease, type C1 phenotype and controlled deletion of Npc1 at 6 weeks of age did not alter the progression or lifespan from the time the deletion occurred [27].