NPC1 and nasopharyngeal carcinoma: However, whereas our results suggest that glycolysis increases in the early stages of NPC disease, these authors concluded that glycolysis was generally downregulated in NPC disease, based on their findings of decreased levels of glycolytic triosephosphate isomerase in Npc1-/- cerebellum at 5 weeks of age, and of decreased deoxyglucose uptake in cultured primary fibroblasts from human NPC patients [71].