More research is needed to understand the impact of pathogenic variants in NPC1 and NPC2, including, but not limited to: first, long-term follow-up over at minimum 1 decade (if not life-long) to systematically assess the dynamics of NPC traits, and second, a genotype–phenotype correlation that to date has been impractical, owing to the size and complexity of the NPC genes. This evidence concerns the gene NPC1 and nasopharyngeal carcinoma.