Niemann-Pick disease, type C1 (NP-C1) is a rare and progressive neurodegenerative lysosomal disease caused by mutations in NPC1. Cells with a defect in NPC1 lead to the endo/lysosomal accumulation of unesterified cholesterol and glycosphingolipids (Ory, 2000; Vanier, 2010). The gene discussed is NPC1; the disease is Niemann-Pick disease type C.