NPC1 and nasopharyngeal carcinoma: These investigators measured the concentration of cholestane-3β,5α,6β-triol (3β,5α,6β-triol) and 7-ketocholesterol (7-KC) in patients with NPC1 mutations, and found that, in particular, 3β,5α,6β-triol was increased in the plasma of NP-C patients compared with controls [31].