NPC1 and nasopharyngeal carcinoma: While substantial evidence [8], [9] supports a direct role for the NPC1 and NPC2 proteins in cholesterol homeostasis, the persistence of ganglioside storage in chronically CD-treated NPC mice, and the apparent dependence of cholesterol sequestration on GM3 in the studies mentioned, continues to raise questions about the overall role of gangliosides in NPC disease in relation to cholesterol sequestration.