NPC1 and nasopharyngeal carcinoma: NP-C is rare, with a ‘classical’ clinical incidence of approximately 1:100 000.4–7 It follows an autosomal inheritance pattern, the result of mutations in one of two genes: NPC1 (chromosome 18q 11-12) or NPC2 (chromosome 14q 24.3),8 with NPC1 accounting for 95% of cases.4,6 However, unusually, neither of these genes encodes an enzyme; they encode intracellular transporter proteins: NPC1, a late endosome/lysosomal transmembrane-bound protein and NPC2, a soluble protein.9