For 10 patients in which plasma oxysterol levels were measured at visits for which scoring could be performed, scores correlated well with mean 3β,5α,6β-triol and 7-KC levels, which supports the hypothesis that the NPC-cdb score is a reliable indicator of NP-C severity (Additional file 4: Figure S1). This evidence concerns the gene CALCA and nasopharyngeal carcinoma.