The depletion of mGSH levels has a severe impact in NPC disease, as inferred by its replenishment with GSH ethyl ester (GSH-EE), which restored the mGSH pool in liver and brain of Npc1−/− mice and in fibroblasts from NPC patients, leading to increased median survival and maximal life span of Npc1−/− mice, protection against oxidative stress and oxidant-induced cell death and restoration of calbindin levels in cerebellar Purkinje cells, which improved locomotor impairment in Npc1−/− mice. The gene discussed is NPC1; the disease is nasopharyngeal carcinoma.